Letsencrypt SSL issue

Our system was upgraded from Ubuntu 18 to 20 recently. After the upgrade, there is some issue renewing the Letsencrypt SSL for a site placed on a Nginx server, though we never faced this issue before. However, we also have apache server that did not show any issues after the upgrade. Any suggestions on how to successfully renew the SSL certificate for a Nginx server?

What client are you using to renew certificates?

Resolved. For details, if interested, check out this Letsencrypt thread.

I just have a quick follow up question. I have added http to https default redirect, which is not working now after adding htpasswd. It works after authentication, though.
Any suggestions on how to fix in htaccess file?

Another Nginx server is fully functional. All the https redirects are functioning too. However, www to secure non www or vice versa is not working. So, does htpasswd?
Added the htpasswd folder file and optimized the config file accordingly.

Any suggestions for this one would be appreciated too.

I have another issue with a reverse proxy server with Letsencrypt SSL renewal. I had manually renewed the SSL and added the corresponding .pem files in the vhost. However, I am seeing issues with renewal. I tried out different variants in the vhost configuration, but the issue still persists. Any suggestions on this front to address this issue would be appreciated.

The domains in question are:

Linux sysadmin blog - Linux/Unix Howtos and Tutorials - Linux bash shell scripting wiki