Baby's rapid weight changes and blood tests

[JoLo2523]

This will be super long so i apologies but really hope someone can help!

I had my lo in may 2023 and he was exclusively breastfed. At 1 week old he was admitted with jaundice and recieved light therapy. I had to use formula and expressed milk between feeds to flush out the bilirubin.
He got discharged and we gradually switched from combi feeding back to ebf which was advised by the HV. At around 12 weeks old he stopped gaining weight and didn't gain for about 2 months (he ended up below the 0.4th centile). He started being mixed fed again and shot up to the 95th centile within a few months. Between 6 months and 1 he had some tests done which showed very mild liver inflammation. He had a recent ultrasound which showed the inflammation is gone but his ALT is still a tiny bit high.
I guess why questions are:
Did anyone else's LO have any sort of liver inflammation that lasted a while?
Does anyone know if neonatal jaundice can cause liver inflammation?
Or anyone who had a LO who was malnourished/ gained weight really fast had any form of liver inflammation?

I know that breastfeeding itself can cause slightly raised ALT. There are also lots and lots of viruses that babies catch that cause mild liver inflammation (that resolves by itself). Is your paediatrician worried about the ALT?

Thank you for responding!
Not particularly but he has had it for about a year and a half and uts never gone above 70, they're going to start running tests for viruses etc and of course Dr Google has told me he has hep B or C or will need a liver transplant and I'm now petrified🙈