I’m adding this comment for something for you to try, but also because I always have this issue, can never remember the fix, and then end up spending a ton of time on the forum looking for the answer, only to have nothing I try work.
Some home cybersecurity products will cause issues in the same way that adblockers do - specifically firewalla and pi-holes in my experience. If you turn them off, you can get the training to work.
