SMTP Error: Could not connect to SMTP host

I have WordPress SMTP installed to get more control over my smtp settings, and it’s been working just fine until 3 days ago, when it suddenly stopped (without any changes on my end, although I seem to notice that something breaks whenever a new version of WordPress comes out). I have a support ticket out to my host, but is there anything on my end that could be causing this? (And is there any way to get more info on what’s going on, other than “Error: Could not connect to SMTP host”)

Gmail is handling my site email, smtp is on port 465, ssl.