So they pushed a new version to GitHub late september:
https://github.com/WCHSoftGroup/ch34xser_macos
This should be the maintained version ahead of what they offer as a download on the official website.
Common other issues:
- When reinstalling, make sure to first remove all old files:
sudo rm –rf /var/db/receipts/*CH34xVCPDriver*.*
sudo rm -rf /Library/Extensions/CH34xVCPDriver.kext
also don't forget to check for any related files in /dev/
and the .app file in your applications folder if these already exist.
Restart the device before reinstalling.
Restart the device after installation.
Try a different USB-Cable / USB-Hub.
Note: steps listed here were reportedly solutions I came across during my research which worked for other people and my colleagues. For me it still doesn't work; but I am using a lot of unstable builds for my OS and other software that might interfere.
Update February 2022: Now with Monterey out of closed Beta this works like a charm for me. At least for the Web IDE.