I'm guessing that's an old screenshot? We renewed our SSL certificate on June 15, 2019. We were a few hours late doing so.
Either way, Google do a great job at ruining the internet and that message is inaccurate in every possible way. To say the connection is "not private" is incorrect as the request was still served via the HTTPS encryption protocol - the issue was simply that it wasn't confirmed/certified by an authority like Comodo, Symantec, or in our case, Let's Encrypt.
Anyways, to proactively prevent such an issue from occurring again, I've now set up monitoring which will send cawfee & I an email 7 days prior to the certificate's expiration date so that we can ensure it gets renewed properly