New bedroom smells of onions?!

[Twinmama32]

Recently did my daughters room- plastered, painte, new carpets, blackout curtains and furniture. Reused an old but virtually unused double mattress and pillows for budget reasons.
It was all finished at the end of September, the last month or so randomly it smells of onions/BO if the windows aren’t open. What is it?!
I’ve bicarbed the mattress, currently washing the two individual duvets, I will tackle the pillows tomorrow.
I change the bedding every week, she showers every night and is only 9 so not mega stinky yet,She does use deodorant. I hoover once/ twice weekly and air the room most days.
I’ve recently read on a thread it could be the blackout curtains purchased from Dunelm...,has anyone else had this and gotten rid of the smell?

It’s not the paint is it? What paint did you use?

Oh, I just googled blackout curtains. Lots of suggestions there but it seems like smelly curtains are a big problem

Dulux kitchen paint because it’s wipeable.

Oh no!! I’ve not googled but I’m going to now!

Such as shame as it’s so cosy.
Interestingly my son also got new Blackout curtains from Dunelm but we’ve not painted his room yet, and it doesn’t smell. He’s also 9....

Unfortunately a search for ‘Dunelm smelly blackout curtains’ brings up many, many hits and not a lot of solutions (other than returning them).

Oh that’s not good....Seems like sun is the cause, DDs bedroom is south facing
I bought them months ago and no longer have the packages.
I think we might have to put up with it till the new year as budget won’t stretch to new ones right now....

Do you have some sort of proof of purchase? (If they’re faulty like that you can’t be expected to keep the packaging.)
I came across a thread on their Facebook page, you could try contacting them there?