If you have had G2 before on the same system, then you are probably victim of the known resolution bug where you are stuck at max 3240x3240 or something like that, which was suitable for G2 perhaps but not Crystal. Even if you set resolution at Max in Pimax Play app (which would be 4500x5100 or something like that) you still only get 3240x3240, and that is also so even if you manually higher in SteamVR .
The error is in a file called “steamvr.vrsettings”, normally located:
c:\Program Files(x86)\Steam\config\steamvr.vrsettings
In there find the line ‘maxRecommendedResolution" = 3240
And change that to…. Dunno, much much higher.
If you don’t see much difference then…… check your eyes - or there is something wrong with your Crystal 
Be aware, that bug might reset it back to 3240 later some has reported. It’s not Pimax fault but SteamVR I guess.