THIS crosses the line - by exactly 349 miles

Yes, I would be suspicious.

Has he got the job yet? Can you encourage him to get so instead jobs more local. Maybe stress it’s cheaper on petrol, overnight accomadation etc. the money he spends on this would negate any pay rise etc.

I haven't read your other thread OP so I don't have the full picture. But my view is also not clouded by it so I will comment purely on what you have posted here.

You are right to feel suspicious about this "coincidence". Over the years, I have seen post after post from women who find their lives blown apart by their dh's actions. All too often women look back and can pinpoint when their spidey senses were first alerted to a change in behaviour. Which they ignored.

Your DH's behaviour may well be above board and he may just be wrapped up in his journey of self discovery to see how this all looks. But there is nothing to gain in you concentrating on this woman. Focus on him, watch and bide your time.

I like the suggestion upthread of telling DH that it would be a great idea for you to go with him once a month so that you can have time together. Perhaps suggest this and see his reaction.

I totally get you OP, I'd be heartbroken over it tbh!
What have you actually asked and what has DH said about her?

I remember your other thread OP - I posted on it.
Just had another look at it and I can't see that you have said what your DH has actually said to you when you have broached the matter of his infatuation with this woman. What did he say when you told him about your concerns?

Seems to me ATM he is in the process of checking out of your relationship so you really need to think about how you see your future. If you both have such different views on what you lives look like going forward and they can't be reconciled then perhaps you would be better calling an end to your relationship.

How lovely of him to provide a little hotel break for you both when he has to pop off to the office each month. Of course you'll be going with him to explore during the day when hes in the office and to have a date night out later. So nice to have a regular break to look forward to...

You were the person who described the woman your DH met at a retreat as a nymphomaniac gymnast with below the face alopecia, and you appear to have spent every second since his return forensically analysing all group photos and reels to see how long she’s in shot?

Honestly, your posts suggest you’re an incredibly melodramatic, borderline paranoid individual. I used to commute internationally for work, so three hundred and something miles once a month doesn’t sound wildly unusual, but you haven’t said whether the office location is in a tiny town or a substantial city? I mean, if your DH has managed to find a job at an organisation whose head offices are in some obscure one-horse town he’s unlikely to have even heard of before meeting her, sure, but if it’s in Leeds or Edinburgh or somewhere, I’m not sure what the issue is?

From what you say, your DH is having a classic response to an intense group bonding experience and is thinking about reinventing his life subsequently. I’m not convinced from what you say that his attraction to her is any more than afterglow from the retreat, but, either way, what are you going to do about it?

Agreed but in answer to your question, yes I'd be concerned, seems like he has checked out of your relationship and has hit his mid life crisis era. How invested are you in your relationship? Do you want to fight for him or would you be comfortable splitting up if this behaviour continues?

Why not post this on your existing thread?