Did you even READ my initial post? It's not that long, I'll repeat here:
php 8.1, Joomla 5.1.1 clean install. Installing downloaded "unei_template.zip", enabling in Styles and see lots of crap.
Do you really think that for using your template I have to install "quickstart" (which is Joomla4, by the way? What if there is ALREADY lots of content on my site?
Please, just follow normal people path - install joomla5 and move on to your template, see errors, FIX THEM FUCKING UP, come back here, let me know the outcome.
OR JUST DON'T ANNOUNCE THAT THIS PARTICULAR TEMPLATE IS JOOMLA-5 COMPATIBLE!
I pay enough on YEARLY basis to requre from you that your JOB being done.