GTA V PC protentional limiter

[evil_genius1]

My pc runs most games with solid fps and average 70%-90% CPU and GPU usage
however with GTA V every time I play this game my usage of BOTH is around 40%-60% the game can hardly run normal let alone high (40-60fps with sudden fps spikes), I managed to get it to use 70%-90% once when I first installed MSI afterburner and it ran perfectly smooth on VERY HIGH. This is crazy and driving me mad. 

my pc specs are
Graphics card: MSI R9 290X series
Processor: Intel(R) Core(TM) i5-8600 CPU @ 3.10GHz 3.10 GHz
RAM: Corsair Vengeance LPX Black 16gb 3600 MHz DDR4 Dual Channel
Monitor: ACER S240HL 60hz (I use 2 but this one for the games)
Motherboard: Gigabyte Z370P D3

Any help is much appreciated as I have ran out of ideas

[evil_genius1]

extra information, I managed to load it up with solid 80fps at set by "RivaTuner" 

relaunched it

fps dropping like crazy.

[evil_genius1]

I accidently discovered the fix and its a GTA V bug exclusively

if you launch GTA from the .exe it loads social club and then solid fps

if you close GTA and then load it from the social club launcher your FPS is all over the place

There's no reviews for this so maybe its a new bug for certain pc's

Thank you for taking the time to read my question