Thanks for flagging. opsindev.news is hosted on GitLab Pages using Let's Encrypt. Maybe the TLS ciphers or versions do not match. Which error message do you see, browser/OS and location may help (if you want to share)
If the MkDocs website does not work, suggest the following workarounds: Newsletter issues in [0] as markdown files, example [1] or the newsletter archive on Buttondown [2].
I'm using Buttondown to send the newsletter, MkDocs serves as web-searchable archive. Kudos to Michael Hausenblas here for the idea, he publishes the o11y.news newsletter.
[0] https://gitlab.com/dnsmichi/opsindev.news/-/tree/main/docs/a...
[1] https://gitlab.com/dnsmichi/opsindev.news/-/blob/main/docs/a...