I downloaded Minecraft two weeks ago. I am on a Windows 10 PC. Until today I have been able to connect to a friend's world they created on a Nintendo Switch, but I get the "unable to connect to world" message when trying to connect to worlds made by friends on a Window 10 PC. No one has been able to connect to worlds I have made.

Today, I uninstalled and reinstalled Minecraft. This did not fix the issue and now I can no longer connect to any of my friends world whether made on their Nintendo Switch or Windows 10 PC.

I can still make and play in my own world. I have been able to connect to Minecraft Servers this entire time period.