How to resolve "Cannot connect to AppleID server" error on macOS?

This is a problem that is getting bigger and bigger for me. My Apple ID works perfectly on my iPad and iPhone. I can change the password etc and it all works fine. On my computer however it continues to give me the message (Cannot connect to APPLE ID SERVER).This means I can't backup to icloud or do any updates etc. I feel like I have tried everything imaginable to get this to work including talking to APPLE SUPPORT on the phone. WIFI connections all fine. This has been a problem I have had for quite a while. Any suggestions would be greatly appreciated. Thank you