How to remove a friend from my list?

[SP4OLI]

Hello!
I can't delete a friend from my favorites list that is written in lowercase letters. Large letters work well, I can add and remove them without any problems. But the lower case letter, I don't know how it got there.

log4om.png (9.25 KiB) Viewed 2034 times

[G4POP]

Select from list and right click (Add/Remove)

Untitled.png (23.73 KiB) Viewed 623 times

[SP4OLI]

Hello. I can only delete SP4API because it is on the list but sp4api is not on the list so I can't delete it.