Have you tried burping more frequently, also when burping try supporting her head, hand under bottom and wriggling in a circular motion mat help to relieve trapped gas. If that's the issue, sorry If you kept feeding her, what happens?
My little boy did the same from about 6 weeks I had to stand up with him flat against my chest and bounce a little and the burps flew out and he would then drink more but it would happen again quicker so I’d have to do the same again he stopped doing it around 9/10 weeks i put it down to witching hour as it happened more in the evening but try standing up and bouncing a little it might help x
Yes ours used to do this, just still hungry. Standing up burping over shoulder helped us
Mine is the same, someone suggested to me to wind them whilst they have a dummy in their mouth (if you use them ofc) and I've found that helps but that's normally my last resort x
My newborn did the same (stiffen up/ legs and back straighten) when i took out the bottle. I learned it was because she was still hungry and that when she’s actually full, she gets sleepy when im burping. Could this be the case