Your cactus are super etiolated. The new growth is reachin for that sun;)! If this were mine I’d cut the etiolated pieces off with a clean sharp knife, and begin to acclimate the cactus to stronger sun.

Not sure if you know this, but those little white fuzzies are called glochids. Protect yourself from the, because they will get stuck in your skin, clothes, and everywhere else. Glochids are VERY irritating.

Thank u so much ! I´ll def cut those pieces !

Be sure to transition into much more light or they could well grow Again.

That etiolation actually looks pretty funky. But I guess you'll have to cut them off as Kara suggested. They don't fix themselves and if they ever grow proper pads, the whole thing will just collapse anyway.

You have said ´they don´t receive sun at all´ - so you know what the problem is and therefore the solution,.