To think the teachers resent me?

The tone of your post does come across as a bit smug and superior. Like you think you and your methods are brilliant and the other teachers (who let them ‘scream/run’??) are a bit crap. Maybe this is the vibe that you are giving off and it’s annoyed some colleagues. I don’t know. It’s a bit unusual for a SLT to be so involved in what sounds like lunchtime for EYFS. Maybe they are not very nice people?? We all have colleagues we just don’t jell with.
Have a word if it’s bothering you that much but you’re only there 1 and a half hours a day and it sounds like you have a couple of colleagues you get along with and the children like you so I’d just be ignoring and getting on with my day.

I would get really fed up with someone singing every time, if I'm completely honest. Is it actually part of your role to sing and tell stories?
You do sound a little 'my way is the only way', children do need to run and maybe even scream a little at breaktime.

Find somewhere else and tell them to stuff their job. Life is too short for this sort of nonsense.

The culture in some primary schools is awful. What's the head teacher like?

The impression that your post gives is that you believe other staff to feel undermined or jealous because you do a good job of managing the children.

You mention that you used to be a teacher and I wondered whether it is in fact you, in your new and more limited role, who feels a need to prove yourself by demonstrating your skills - so that you unconsciously hold out your good management of the children as a kind of badge. You may be implicitly courting the approval of the other staff

Rather than being resentful of your skills as such, the staff may be picking up on this anxious need to assert them, and reacting to that.

I get that everyone wants to feel valued and that the job they do is important - but you’re lining some kids up and putting hats on them. If SLT approval is important to you then you probably do need to go back to actual teaching so they notice your contribution a bit more. I’m a bit confused about who you feel has an issue with you and why you think it

I think it's most likely that the SLT don't speak to you much because you are a midday supervisor. If you want SLT conversations, and to be noticed, you should go back to being a teacher. Your job is just currently not that important and does not require teacher training. It smacks a little bit of showing off.

Also, if you think you are better than the actual teachers, you should do the kids a favour and go back to teaching. There are breakfast clubs and there is part time work to accommodate your school run.

It’s still a bit hard to picture as the sun hats and running around feel outdoor but then you say it’s on the teachers carpet. But I have just woken up so maybe I’m being dopey. I guess you are doing more than many a lunchtime supervisor, if that’s what you are, and are being more like a teacher. Which isn’t a bad thing but institutions can be funny about status and hierarchies. It’s a nice thing you’re doing but unusual and maybe you’re annoying people. If you care what they think, you could do less and still be doing a good job, but more likely you’ll do what suits you and the children and be glad you only work lunchtimes so don’t have to get involved with such politics.

If you used to teach it could be that they resent your 'easy job' or it could be that as a teacher you didn't notice the hierarchy in the system as much. Why would the SMT be chatting to you? They are several pay grades above you now. Or maybe it is your imagination. None of these things relate to you as a person, they just see you doing that role.

There's a whiff of superiority about your post, which could rub colleagues up the wrong way

But how can strangers online guess what's going on, or not?

If you're really concerned, ask a colleagye

I think you could outright ask them? Or ask your supervisor to? It’s obviously weighing on your mind.

The only thing that stands out to me is the story time. If they’ve already been sat on the carpet for five minutes then that’s five minutes less that they’ll be able to concentrate for the teacher for their input.

It's probably a white coat blue blazer thing. SLT don't always acknowledge non-teaching staff as equals, regardless of what you're doing.

But also, it might a bit weird for you to take it upon yourself to change up this whole transition period without discussing with the classroom teacher. Like, I can completely picture both scenarios - one where you're being perfectly reasonable and making a very small adjustment to some dead time, or the other scenario where you're overstepping and taking over too much.

It’s lunchtime and all you’re doing is putting hats and cream on. There don’t need to be sitting beautifully at this time, they need to make the most of the time they have where they aren’t being told what to do.

I doubt the teachers give much thought to you as a person, but they might not like your practice if it is time consuming and unnecessary.

who are you getting this vibe from daily? Are the SLT coming to watch this lining up like it’s the changing of the guard?

It sounds like a nice way of getting them calm but the teachers probably have they own routines for calming then once they reach the classroom and the lineup storytime is delaying everyone.
Why don't you ask what suits them? In that scenario I would defer to what suits their teachers who have to manage the full day

Surely they are just getting on with their own jobs. Thinking about data and other nightmare stuff. Maybe they don’t see a need to talk with you as you are doing what needs to be done.

If they thought you were doing a bad job then they would speak to you rather than ‘send you to Coventry.’

At various times we need to line children up, gather them together to put sun hats on etc. Many staff let them run/scream to do this. But I prefer to get them walking rather than running, sing songs or read a quick story which keeps them calm.

The only thing I can think of is you’re making a bit of a meal out of lining them up, if you’re reading a story (!) to get them to line up to get their hat on surely that’s just taking ages and getting in the way?

When I was teaching we used to find it really difficult to recruit midday supervisors - the hours are inconvenient (not close to drop off or pick up) and the money earned is minimal. So if you get 'bad vibes' where you are I'm sure you'd be quickly snapped up by another school. It's great that you can line them up quietly and get them to walk but I shouldn't think the SLT would be jealous of that (if that's what you are implying), that kind of thing will be second nature to them.

Is the implication here that you're much better at getting the children to sit nicely than the teachers and therefore they are jealous and resentful of you?

I don't think any of us can confirm that! It seems unlikely but perhaps you work with very petty people!

I just can't really picture what you mean as someone who works in a school. Are you a midday supervisor? Are you talking about lining them up to go in/ out of class/ to get their lunch? If so as long as you are managing their behaviour what could be the problem?
If they're waiting for you to bring their class in and you're out there reading a story to the line, I can see this would be annoying!

Surely if you’re doing a 5 min story every time they need lining up, that’s taking up a fairly large part of their play time?