CBsubs settings page - huge delay to load...

When I try to open "Paid Subscriptions | Settings" it reliably takes EIGHTY-FIVE SECONDS to load the page!!
No error message, just the slow load. Other CBsubs backend pages are fine: they load a second and a half, or less.

What could be slowing it down?

"You have the latest version 4.1.0+build.2016.08.23.14.36.51.131849874".
CB version 2.1.2
Joomla! 3.6.5

Possibly the OpenSSL or version checker. Do you have any sort of firewall that could be blocking the outbound version checker HTTPS request?

No firewall, no.

Could it be due to a CB plugin that is installed but not active? I also get a 15 second delay when opening a subscription plan (CB Paid Subscriptions: Edit Subscription Plan) - that page opens fine but gives the notice:

No that shouldn't be a problem. Press F12 to open your browsers developer console then select the Network tab. Now visit a slow loading page to see if your issue is due to JS (you should see at the very top the DOM request and it should have a time purely for that request). Do you have a lot of fields?

We don't have an especially huge number of fields, I don't think... if you mean "CB fields", the _comprofiler_fields table has 48 rows.

Looks like javascript is loading quick, the big delay is the initial page request "1.4 MINUTES"... slow query, perhaps?

Check out the network report, below... everything spills out fine after that huge initial delay...

Maybe the Paid Subscriptions | Settings 'menu link' is mangled somehow? (Perhaps its some legacy menu link that somehow didn't get updated?)
We have been running CBSubs continuously since Joomla V1.5... upgraded to 2.5... then upgraded to 3.X (now 3.6.5)

here is whats calling that uber-slow page:

Then it is obviously server-side related.

If you turn Joomla site debug (2nd tab in Joomla Configuration) to on just the time to load that page, you should see at bottom a debug module that is an accordion, where you might find the reason of the the major delay.