When opening the Minecraft launcher an error message pops up saying 'We were unable to verify what products you own. Please check your internet connection'

I have owned minecraft for now what must be close to 10 years and have a very strong internet connection, I have also uninstalled and reinstalled the launcher about 5 or 6 times, I’ve signed out and re-signed into my accounts multiple times and followed every YouTube tutorial to try and fix the issue however nothing I have tried has worked. Sometimes the error message doesn't pop up but then when I press play to see if it will finally work it asks me to enter a username but is won’t let me press complete when I enter my usual username, it’s just greyed out and says failed to request username availability.