Did you send another member a "Friendship Request" recently?
When you click on the "Add as Friend" link on another Avalon member's user page, you get the option to "Also send a friend request" to them. If you sent anyone such a "friend request" between about 26 April and 13 May, of 2024, they probably did NOT get that request, through no fault of their own.
A comedy of confusions, changing email servers, changing email standards, and inconsistent application of email standards combined to mostly break the Avalon forum's email sending, which is used to send such "friend requests."