for me it works Even it has the security padlock! For you probably is a caching or dns caching issue (clear them) or use another browser or at least use a VPN!.
Some browsers, notably Google Chrome, tend to cache SSL certificates for a long time. Can you try to open your website in private browsing mode and see if you still get that error?
The SSL issue is related to the specific browser, so clearing DNS caches or switching networks probably won’t help.
If the issue persists for over 3 days, I personally had to change my DNS provider to CloudFlare (1.1.1.1 & 1.0.0.1), and then SSL worked on my network instantly.