possibly starting teething? my daughter is the same age and is also doing this, spitting up more than usual as well. is your bub drooling too?
My LO does the same but she is 6 weeks old. Especially in the evenings... I switch the boobs or give her the bottle with my breast milk. My husband usually takes that feed as it seems easier. Maybe sucking from the boob is harder than from the bottle and she is more tired in the evenings...
Thanks for your help everyone. @Keita we wondered whether he is teething as he is drooling and constantly eating his hands (and mine!) and I didn't realise this is another sign... @Kate I've tried switching him and he does the same on both sides, though I think milk is down in the evenings (especially on his favourite boob) @Lucia he definitely seems to tire and usually has milk from a bottle in the evening... But sometimes has both haha
Have you tried switching him to the other side? My son does similar, especially in the evenings when I'm not producing enough from one breast. Maybe being abroad has changed your intake and might be disrupting your supply slightly?