I use this module in version 2.0 with Nextcloud 16.0.1 and 17.0.2 First i configured the module wrong, but the Support of WHMCSGlobal was very helpfully and fixed the issue directly over the online chat. After that, we have updated to Nextloud 17.0.2. Also with Nextcloud 17 is everything working with that module.
Thanks, Christian for your valuable feedback, this really counts for us. Looking forward to serving you more.