How to Downgrade to Old Version?

I have install the latest version to my new server, but I got so much error like:

• When add a website, I choose php 7.4, but after installed WordPress it’s will automatic change to php 8.0.3.
• After 2 days some my site have error like, mysqli extension not install, server error and other, but another site running normal. I reboot the server, all site is normal. the next day another site has error like that. That error got on random off my sites. But all my sites running normal on my another server has old CyberPanel version.
  Can some one help me?

right now 2.3.5 version is the stable version but may be you missed something that’s why you are getting these issues.

1. check whether your domain is on pure ols or apche as the backend.
2. all basic extensions come with installation but sometimes with most advanced PHP versions or most old PHP version you need to change add the extetions.

All my sites is use WordPress CMS and running normally on CyberPanel v2.3.4, so I think not problem with the backend.
I have install the same extensions like my old server that install CyberPanel v2.3.4, but on the latest stable version I got error like I say before.
So, If can downgrade to old version, I am so glad.
Because now I got an error that can’t be found what error on error logs.
I don’t know why the sites suddenly an error even though previously it was running normally.