GTA V Lag to play and with broken graphics?

I already completed this game story mode with the same system but when i try to play from the start again it becomes laggy and unplayable driving in the city make the graphics broken like no floors, sudden appearance of buildings etc. I dont know what snthe problem. System spec Ryzen 1300 @3.6ghz Ddr4 8gb ram g... show more I already completed this game story mode with the same system but when i try to play from the start again it becomes laggy and unplayable driving in the city make the graphics broken like no floors, sudden appearance of buildings etc. I dont know what snthe problem.
System spec
Ryzen 1300 @3.6ghz
Ddr4 8gb ram g skill
Gtx 1050ti 4gb
Resolution: 1680x1050

But when i play other game like witcher 3 doesnt have a problem
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