If you’re having this problem it’s most likely that you’re in a part of the story mode where Mike and Trev have been banned from the city. When playing as police officers the characters are recognized by the game as Mike. If you enter the city with an officer from lspdfr or most of the in game NPC’s that you can use with a trainer this will keep happening. If you switch to Franklin the enemies should instantly go away. Just progress further in story to when Mike and Trev may return or don’t play that far into the story.
“SOLVED”