9 week old refusing milk, difficult to feed - formula fed

Hi

My DD is 9 weeks tomorrow and for the past week she has slowly been going off her milk and it’s getting worse! She’s formula fed and usually guzzles it but somethings changed this week. She had her jabs Wednesday and I’d put it down to that but she was doing this for a couple of days before..

She fights it, cries and I have to go though a ritual of dummy out/bottle in and vice versa to almost trick her to get food in

She tends to take it better in the night but after is basically squirming and fidgeting all night and then wakes every couple of hours, not crying in pain but seems uncomfortable. Prior to this week she was waking for feeds every 3-4 hours but going straight back to sleep again fine. She is getting impossible to burp too and again was fine prior to this last week!

She’s having approx 200-300ml less a day than she was so a good couple of bottles

I’m going to take her to the HV weigh clinic next week but any ideas in the meantime?

I have tried changing her teat from size 1 to size 2 but made no difference although we have kept size 2 as it’s not flooding her either!

Today all I have got in her since 5am is 1 x 5oz bottle over a course of an hour battling and 1 x approx 2oz which basically forced into her, she point blank would not take anymore.

Also she’s sleeping more in the day which I would usually be pleased about but it just doesn’t feel right, it’s not like her..

Is this reflux type symptoms? Can this even start this late? I thought was more common to start in the first few weeks - she isn’t sick and never has been

At a bit of a loss so any more experienced mums have any words of wisdom?