Facebook Messenger - Suggested Friends

Hi I’m wondering if someone can please help me / explain why ... So When you search in Facebook messenger for one of your “friends” to message it comes up with “Recent Searches” which you can edit / delete o people in your recent searches and then it also has “suggested friends” which you can’t edit and I was thinking this is a list of people you usually contact or recently have contacted except for some reason in my “suggested friends” is someone I have not contacted in quite some time not on any Facebook forum, phone or other apps and they are second on my list. Why would that be?