Highly unlikely what I am about to say is the cause of your issue IMHO but .local is bad idea to use as a TLD as it is reserved for and used by other services that you might possibly have on your network.
Ideally you should should use your external real domain and then stick something in front of it e.g branch.domain.com, you would then have a server FQDN that looks something like servername.branch.domain.com.
Arguably many small businesses that do not plan to operate on multiple sites or with multiple sub-domains can get away with made up .gibbgerish TLD's but there are many arguments against it. Perhaps the best is that you cannot get a real Certificate issued against a made-up domain.