It is indeed great that you figured out what the issue was and congrats. But please let me point your attention to 2 things:
- Quite a few people here are running Nextcloud instances without issues. I too am running half a dozen Nextcloud installations with no real issues, so it seems Hestia and Nexctloud like each other
- You were considering to completely drop the idea of running Nexctloud on Hestia and thinking about going back to Vesta instead. Dropping a well supported software, without security issues (like Hestia), to use a software that is not secure and has limited/problematic support, does not sound like a good idea. I may sound like a Hestia “fanboy” but to be honest this is not my intention. IMO it is always better to spend time to fix the issue at hand, than to settle for “less”. This remains true even if you omit the names Vesta & Hestia
Last but not least… Taking the time to find what the problem is, will also provide you with knowledge and skills! Which are always needed when using software that requires sysadmin skills.