I agree..
Bought the VA-400 with the USB connection a few months ago. It is supposed to be high resolution but I can only get it to work in the original low resolution. Apparently it does not play well with some Samsung devices - like my S10 and my Samsung tablet.
The apps that Ablescope (OTG View & CAmera Fi) provides don't work at all on either of my devices.
After trying a number of other apps, I found one that kind of worked. Low resolution and frequently won't connect to the VA-400 requiring multiple starts and stops and unplugging and re-plugging in.
Also Ablescope advertises an adjustable dimming light but in fact has only two positions - very dim or full bright. Made it useless for looking in the gas tank where the dim was too dark and the bright setting created too much glare to see much of anything.
About 5 years ago I bought a cheap Centech Inspection Camera from Harbor Freight with a 2"x2" screen. There is no question that the HF camera gives a clearer picture than the $300 VA-400 from my experience. Of course, it's no good for cylinder inspections (no articulating head) but for other things its better. And works every time, just turn it on.
Will be selling the VA-400 shortly. It was ok for the cylinder inspections, but for everything else my HF unit is superior. I'm going to try the Teslong for future cylinder inspections (and less aggravation!)