h1z1 huge fps drops in towns

it all started few months ago when i re installed my amd radeon software.i used to play h1z1 at 80-100+ fps without any issues,after the reinstall whenever im in towns i barely reach 40 fps & its highly unstable.ive done all the suggested things to fix my fps ingame(render/useroptions etc.)& also contacted daybreak support & they couldnt fix my problem.

CPU:intel i5 7600

GPU: amd radeon rx460

RAM: 8gb