Friend disappears off my list after I name change?

I did a name change earlier tonight and a friend messaged me about 5 minutes later (discord) asking why I deleted them on league. I said I didn't, went to my list and noticed they were missing. I opened chat logs and sure enough my tab with them was missing. I immediately tried sending them a friend request and it went through. Has anyone else ever experienced this bug? I'm incredibly upset as the friend that was effected is really angry with me and believes I removed them intentionally, and I didn't. For what it's worth I 100% believe they also didn't remove me, as it logically makes no sense for them to then point it out and cause drama because of it and that's not at all their personality.