u/Gay-Rights-Litten

This is something that I’ve never seen before. I have a friend who has a Facebook account but no one can send him a friend request. The option is not there on his profile. His settings are set to public, we checked. Additionally, when he tries to send a friend request, the add friend button will remain blue after clicking it. It does not turn grey to indicate that the request has been sent and I do not receive the request. Facebook says his account is in good standing (no community guideline violations or restrictions) and he has cleared out his outstanding friend requests. He has not done anything unusual with his account, just normal things. Anyone know why this might be and how to fix it?