7 week old only feeds 5/6 times a day for 5 minutes. PLEASE HELP!

[Glentul]

Hi!
My daughter is 7 weeks old and around 3 weeks ago was the perfect feeder, piling on the weight of around 14oz a week. Suddenly one feed a day would result in her screaming and sweating etc. We were told that basically she's eaten enough that's why she's doing it by the health visitor.
This then escalated to two feeds a day etc till every feed she does this & now she hardly eats. Her weight gain over the past 3 weeks has dropped off dramatically to around 3/4oz a week. We have been to out of hours 3 times, seen the health visitor 4 times & breastfeeding support have been out 3 times.
She’s had suspected colic, reflux, cows milk protein allergy & tongue tie. All have been shown to not exist as it’s been escalated higher up the chain of command if you like.
She has a lip tie but apparently this won’t affect breastfeeding & she takes omeprazole as a precaution if it is reflux as advised. Also the wife has gone dairy free but this has made no difference at all.
Breastfeeding support said she must be an effective feeder but she's not draining & unsatisfied so still hungry but won't eat.
We were told that it’s a developmental stage by a doctor then told to start worrying as she’s dropping percentiles by another.
We’ve tried her with a bottle with breast milk / formula and she does exactly the same with the milk running down the side of her face screaming. So far medically there doesn't seem to be anything wrong with her when they check oxygen levels, dehydration etc.
We don’t know what to do as we don’t obviously want it to get to the point she’s losing weight but seem to have exhausted all options.
Has this happened to anyone before?
Also this is my second child 👍🏻

[BeeMyBaby]

I'm afraid I've not had any experience with sudden change in feeding and you've probably tried already but has your wife tried a different feeding position? With my first, the midwives only told me about the rugby ball hold but that's actually a really rubbish position. Has she tried the laid back feeding position, I can't remember what the proper name is, she leans back and has a pillow proving her up a bit then baby lies on top and matches on. Also it could be from a forceful letdown which I had, the milk comes too fast and the baby can't cope, or the opposite, the milk is too slow and the baby gets frustrated. If it's forceful let down then she should express a few minutes into a muslin or whatever till she can feel the let down stop and then attach the baby.

[OnlyAGirlsHorse]

Check letdown speed as suggested

Something about the change in milk taste perhaps? Examples: nursing mothers diet (there are a few foods that seemed to affect mine). Getting your period is another I've heard frequently. As is being pregnant again (it happens!).

Something else in the baby's environment? Mine used to hate not being able to look out of the window when younger, if I tried "distracting" with bf it was always a fuss, awful latching, basically too much distraction to latch despite being hungry!!