As I said, the problem can't be reproduced.
Apparently, it happens on my entire internet connection: my laptop, my desktop PC, and another desktop computer.
I've tried several things to fix it, and only VPN has managed to minimally fix the error. Afterwards, I've had trouble downloading Minecraft skins correctly again.
From what I've seen, the problem you're having doesn't seem to be 100% the same, because mine happens on my entire internet connection.
The same thing happens to us, I can't find a way to solve it.
Do you see multiplayer skins?
I already did it. I've been on the community discord since yesterday.