
bathroom - no mould previously

bedroom - previous had some mould but cleaned it and repainted.
Hi there!
Hope this message finds everyone well.
I was wondering if anyone can shred some light on what is happening to my ceiling in my bathroom & bedroom.
This is the 2nd time this has happen and I used dulux ceiling paint to paint both times. Installed in my bathroom is also an IXL 3 in one exhaust fan/heater.
The ceiling is getting darker and darker and the paint is starting to peel. I've noticed this in a few other rooms in my house. I've recently repainted the whole house 1.5 years ago. We used the paint as attached.
If someone can kindly shred some light on how to rectify this. It would be great.
Thank you for the help x