From
Web site settings and security for Azure DevOps on-premises :
Self-signed certificates
Self-signed certificates are useful for trial deployments of Azure
DevOps Server, since they are very easy to provision and use. They are
less appropriate for production deployments of Azure DevOps Server,
and we do not recommend they be used for Azure DevOps Server
deployments exposed to the public internet. Generally, self-signed
certificates are susceptible to man-in-the-middle attacks. They also
cause problems for users, since they will cause certificate warnings
and errors until their root certificates are installed on each client
machine.
In other words, every certificate is issued by a Certificate Authority.
In order for it to be valid, the issuing Certificate Authority must
itself be recognized as trustworthy.
A self-signed certificate is signed by the issuing computer, so is valid
within that computer. Other computers will not recognize the issuing
computer as a known authority, so may refuse to accept that certificate.
That is why a self-signed certificate is good for testing,
where all the computers are controlled, but not good for the
wider public.
For your problem, you need to set the other computer to accept
your certificate. Depending on your browser, it may allow such
action. Otherwise, you will need to import the certificate
manually into the Certificate Store on that computer.
