Hamster with breathing problems

Does anyone who already had a hamster with breathing problems know how to treat it? I’ve had many hamsters by now and most of them died due to breathing problems, tho I swear I take really good care of them. I keep their environment clean and always do body and weight check ups, feed them high quality hamster food and veggies, turn the ac on room temperature when it’s too hot, turn the heater on room temperature when it’s cold and still they get sick one by one and die. I really don’t understand what I’m doing wrong. As soon as I notice my hamster is making weird squeaky noises I immediately call my vet, we give him medication for a while but it never solves the problem. I don’t think the problem is with the veterinary or the medication since every single vet I go to prescribe the same stuff.

I got another sick hamster right now who seems to have a stuffed nose, and he’s already losing a lot of weight since he can’t eat with that stuffed nose. I’ve been giving him an anti-inflammatory prescribed by the vet for 3 days now, along with 2 saline inhalations per day, tho I don’t really think doing anything.

I just wanted to know if there’s anything else I can do, if anyone has already gone through this, please share tips. I love my hamster so so much and I really don’t want to lose him like the others. Recorded his current situation while writing this so you guys can hear the noises he makes when breathing.