Gitlab user https certificates stop working after server restart


I have setup a gitlab server, running on Centos 7, my local network, and am using self signed certs to authenticate both the server and users (clients) when accessing the gitlab web portal via https.

This all works fine, until I hardware restart the server.

I can restart gitlab, simply via “gitlab-ctl restart”, but when attempting to access the domain, or ip, the connection is closed by the server.

Further investigation give the following error:
" (SSL: error:0B080074:x509 certificate routines:X509_check_private_key:key values mismatch)"

This implies that the https client certificates do not match to that on the server, yet they have not been altered from before the hardware restart. The certificates are, quite literally, exactly the same as when they are confirmed to have worked.

Can anyone help direct me to figure out how to resolve this problem?

That is, why does a server restart effect these certificates?

I am also a complete noob when it comes to git, gitlab, etc- this was the first time I have ever used any of these tools or any linux based OS so please assume zero knowledge in any replies, many thanks.

My current solution is to roll back to a system snapshot from before the hardware reset and just never turn the server off for any reason whatsoever (which isn’t a viable solution at all).