Glad to hear you figured out. It does look a mystery since normally OLS upgrade won't make such configuration change at all, most likely "//" has already been there before OLS upgrading.
It seems some permission issue. Did you run ./lsup.sh as "root"? If so and still problem, you may log a ticket with us by providing tmp root access so that we can check for you.
Can you try to stop OLS and start OLS again?
Normally OLS should not cause directing issues. If the issue persist after stop and start, please log a ticket with us by providing tmp root ssh for us to take a look.
Thanks for the bug report. Is there any core files? Can you check this KB for steps to log a bug report in our tickets and information our developer need to do further investigation? https://openlitespeed.org/kb/submit-openlitespeed-bug-report/
Have you got chance to check this wiki for right testing steps?
https://www.litespeedtech.com/support/wiki/doku.php/litespeed_wiki:cache:check-pageloadspeed-chrome-firefox
The header seems alway "X-LiteSpeed-Cache: miss" for initial request for a new user hence it will be slow.
Request URL...
maybe you can consider cyberpanel + ols image from Digital Ocean. Once you lanch your own droplet, you can create your domain, then migrate your application code and database to it.
Normally domain is the right way to access to your website, especially you may have multi sites on the same server. You can use ip for cyberpanel or lsws admin console.
If you enabled auto reload .htaccess, it should work too. Make sure to restart OLS every time you make a change to .htaccess
https://openlitespeed.org/kb/how-to-autoload-htaccess-with-openlitespeed/
OLS will normally run as "user:user". If it somehow runs PHP as "nobody:nobody", it might cause permission issue. you can toggle log when it happens and may create a ticket and send the log within the ticket for our OLS developer to take a further look.
Is it a wordpress site? You can use openlitespeed with litespeed cache plugin for wordpress for your site and all free. LSCache will make your site fly. 500 users daily won't be any problem at all. LiteSpeed can server thousands of requests per second.
Do you use any control panel? If cpanel...