Visiting a friend who moved means meeting their new life. Be curious about it instead of jealous of it.

A visit puts you in front of evidence that they have built something without you, and that can sting even when you are pleased for them. The jealous response is to compare, go quiet, or treat the new friends as rivals. Curiosity does the opposite. You get to see the version of them that exists somewhere you have never been.

Ask to be shown the ordinary things rather than the sights. The route to work, the usual coffee place, the people they see most. Be friendly to the new friends in particular, because that is what makes you welcome there rather than a visitor from before.