Hi !
If you can upload it means the the driver is correct. I would look first at wiring if there is no shorts and if pins are in the correct order,look for bad solder, weak connections .... Another possibility is the lack of power preventing the Arduino to correctly start, often bad usb cables or usb hubs cope into play here. If you are using an RGB matrix, power is a huge factor and depending of your Arduino you might need to add an external power supply (it's not required most of the time, but it can happen.) : https://github.com/zegreatclan/SimHub/wiki/Arduino--Setup#powering-considerations
Nicolas
@admin5435 I got a new hypothesis:I bought the suggested Elegoo Nano v3 boards on Amazon and they work! As a user, the difference between all the boards that did not work and the one now working is the BOOTLOADER!
So all non-working boards where using OLD bootloader (in my case). The new Elegoo board uses the NEW bootloader. Could it be that the newest windows driver is not properly supporting the old bootloader anymore (or a related issue)?
For all others that faced these issues: did you exclusively have problems with devices that use the old bootloader?
If that is so, @admin5435 may this be addressed or pointed out in a simhub update, so users will know about that issue(?) Could you research if that is actually the problem?
as far as I can tell, my only issue was the other brand, and I'm pretty sure they were the older bootloader. Definitely a windows driver thing since the old driver was working before it got auto rolled by windows update.
The bootloader only acts at upload, but considering the symptoms I would think more about an issue growing lately: https://github.com/SHWotever/SimHub/wiki/Arduino---Counterfeit-Fake-CH340G-chips-driver-issues
I see. Indeed, my non-working nano has no visible CH340G label on the related chip! Thanks for clearing that up! Another mystery solved!
Is that then witht the others the same? Do your non-working boards have CH340 chips without official labelling?