Username issue

So this bug has been happening to me (on my laptop) for quite some time now, and it's really getting to my nerves. I got Java Edition for free, because I already had Minecraft for Windows, and I entered my username, Cod1ngGamer. It showed that it was valid, so I hit Confirm. Immediately, a red box showed up in the top right, saying there was a problem creating the username. I tried some different usernames, and I just kept getting the same error message OVER and OVER AND OVER.

After a while, it just started spamming errors that it couldn't check for availability. If I exit the username creation interface and open it again, it resolves the confirmation issue temporarily. I've always been wanting to play Java, so this was mildly infuriating. I am also signed in on the Xbox app, MC launcher, and MS store. I have photographical evidence attached and I understand that this is a common issue, but I need it to actually be solved instead of just marked as Duplicate.

I would greatly appreciate it if this was solved, as I have always wanted to get into modding and advanced skins. I just can't easily do that on BE (Bedrock Edition). Please solve. :'(