In case any of you are experiencing issues with updating plugins, or any plugin that requires cURL - and are on a Plesk Control Panel hosting environment, the issue is with an updated version of the server control panel.
If you don’t admin your own server, you’ll need to reach out to your hosting company to have the issue fixed (it’s a basic fix of restarting PHP services.
I discovered the issue when mail was failing to be sent using SMTP2GO plugin and seeing a cURL error related to SSL certificates.
The fix is here: https://support.plesk.com/hc/en-us/articles/18463826337815