www.ultimatehandyman.co.uk

Hi
A bedroom ceiling has 2 bumps lines (bulges), each along the whole ceiling of about 3m and about 4 inches wide. Room is on first floor and ceiling has lining paper. I assume ceiling has been repaired in the past but poorly. It was painted white gloss (had a shine) , I painted it white matt last week. The strange thing the 2 lines of pumps don't show during the day in fact ceiling looks very nice and smooth but at night with ceiling light on looks horrible, I don't know why looks so bad with matt paint? It didn't look perfect with gloss but not this bad. A couple of questions:
1. Is it worth scraping the pumps and repair somehow?
2. Revert to gloss?
3.Can skim over lining paper?

TIA

I just took a pic when dark and light on, pic below. It doesn't look bad at all when put level across, it's minimal of bulge 1mm if that but looks magnified much more when looking at it.

Would a thick plain wall paper laid across over the whole ceiling solve the issue?

After 22 years in the house, I know by now the previous owner was a DIY disaster.