Installation of 3.0 hung at set up and then went blank

I tried installing 3.0 via cpanel using Softaculous installer. PHP had been updated to 8.0 for the domain. Got an initial error message to install zip and fileinfo PHP extensions. Did this and it installed successfully.

When I logged in and started doing the set up, it got hung up on the screen asking about purchasing apps. Closed and logged back in. Now when I log in, it does to the main page but it's completely blank.
I did this update because you the old version I have (and have reverted to) keeps asking for it to be upgraded.

Not sure why I was asked to do the set up all over again. Maybe I should use another method for installation?

Unfortunately, I cannot upgrade from my old version because it won't run under PHP 8.0 (I get all the left pane menus but none of them work if in PHP 8.0 rather than 7.4).

Any help would be appreciated.

A bit of a wall of words above. Perhaps someone can help with first issue I have -- getting verson 2.1.36 to work with PHP 8.0.

When I set the server to PHP 8.0 version 2.1.36 stops working. I can log in and get the left pane menu but nothing on the menu works and the tool bar does not appear.

try to use 8.1. A did that and both version are working fine at same server. Maybe there is a issue with php 8.0 ( rquired ist 8.0.2)