@GTAPlayerN For some reason blips seem to be memory hogs. I encountered this first when I installed some mods which create a bunch of blips. All of the original blips like clothing stores, Los Santos Customs etc disappeared. I think the game restricts the amount of blips in order to prevent memory corruption. Sorry but that's all I can tell.
But why do you even need such a big amount of blips at one place? Wouldn't one bigger blip also serve your purpose (whichever that might be)? That would not only fix your flickering problem but also keep other mods working and eventually not crash the game.
G