Playstation parties banned?

I have recently started seeing parties from people I don't even have on my friends list. Why is that and do you have it too? Lg

This may be because one of your friends is at a party that is not friends with you.

The people on the left are on your friends list. On the right is only the name of the party. It has always been like this.

People are not on my friends list is the problem.