Thanks for send us the sample gerber files. Those Gerber files are formatted as 2.5, during AutoLoad please modify the gerber import settings. This is a one time modification only, and your future gerbers will load fine.
Note: If possible please try to output RS-274X gerber files from PowerPCB. This will allow the Gerbers to load instantly because their apertures and format information will be inside the gerber files themselves.
Here is an online demo for your reference:
Also, PowerPCB is know for outputting the Drill files using a different coordinate system than the Gerber files. So for proper viewing you should use Align Layers. Here's an online demo for your reference: