On rare occasions while playing GTA Online on PC I sometimes notice that my own player icon on the minimap is constantly flashing, what does this mean?
The only thing I could really find on the matter is a Reddit thread. It appears that this happens after you kill someone. It is also mentioned that it could be glitched:
Sometimes they continue blinking after though, and stay that way until they or I leave. Think it's just a glitch.
Since you just came out of a versus match, its possible that your icon was blinking in there after killing someone, and the game ended, it carried over with you into free roam (that would apart of the glitch).
Another forum site seems to suggest it is also a glitch:
Or you might have killed someone and it bugged out so now it's flashing.
Both of these sources also suggest that somehow you may have highlighted yourself, which in itself would be another glitch. It's been a bit since I've played GTA V, but if its possible, see if you can check who you have highlighted.