Issues with Rendering Maps

Hi, I am looking for some help, if Iam in the wrong forum please direct me to the right place.

We have implemented OSM whcih has worked successfully until recently, where the Maps are not rendering, on Chrome. The same solution works on Firefox.

I have been told there is a problem with the certificate

Shows an error.

Thanks in advance of replies.

Chrome version - 87.0.4280.66 (Official Build) (64-bit)
Firefox version - 83.0 (64-bit)

Your web-server’s certificate is not correct:

You are not rendering maps, but using tiles rendered by Wikimedia.

And you are using an old outdated tilelayer URL.

The TileLayer URL should be:


I have not checked their usage policy. Please do that yourself.

Thank you for your reponses.