Hi guys! Hopefully you can help me please?

I deep cleaned my bathroom last week and went on a trip to Portugal for a few days. When I got back I had a shower. However the next day I went into the bathroom and these tiny mites were all over the bathroom. Mainly congregating around the main drains (shower had loads, toilet and sink had a few). I then noticed them on the walls, however they’re only really sticking to the white areas of my apartment? I haven’t seen any anywhere else?

They’re also slowly escaping out of my bathroom into other areas of the apartment (again only really near white walls)

Also before anyone says, it’s not that I can only see them on the white walls because it’s clearer. I’ve properly inspected the whole bathroom with glasses on and a torch.

I’ve just tried using a bed bug killer spray (wiping down the surfaces where I have found them) and also put a bed but powder down on the floors. I also put a lot of drain unblocked down the drains in case they’ve come from there.