Let's Encrypt "manual update" stopped working.

I was trying to find out what caused this issue, https://www.virtualmin.com/node/59402 , and I believe it was a setting in Joomla forcing HTTPS.

But on trying to test this solution if I click the "Only Update Renewal" button, the screen refreshes to the "Current Certificate" page, but nothing seems to happen after that.

In the miniserver.log is this referance, but I cannot find anything else relating to this issue, in any of the webmin logs.

192.168.1.79 - root [12/Nov/2018:07:56:15 -0700] "POST /virtual-server/cert_form.cgi?dom=149126439730026 HTTP/1.1" 200 38321 192.168.1.79 - root [12/Nov/2018:07:56:29 -0700] "GET /virtual-server/letsencrypt.cgi?dom=149126439730026&dname_def=1&renew_def=0&renew=2&only=Only%20Update%20Renewal HTTP/1.1" 302 0 192.168.1.79 - root [12/Nov/2018:07:56:30 -0700] "GET /virtual-server/cert_form.cgi?dom=149126439730026 HTTP/1.1" 200 40523

Any ideas as to where I should start looking?

Many Thanks.