man i should've posted this too, i had this problem for soo long. i "fixed" it by looking around some places to get gta mods until i found one version that did not have this bug.
I remember in one version (when it was still cleo i think), you would go through markers in first person. This version however switches the camera to the default IG-Cutscene style one.
I really liked going through doors in FP, even if there was nothing there, it felt smoother. Would it be possible to have an option to change this via config?