TeamViewer Id and password not shown

I have teamviewer 15.10.5 installed on 2 machines running Linux Mint 20.  Upon installation both worked fine with file transfer and remote desktop. Next day I restarting both machines, one machine disays an id and password, but notthe other.  Niether machin can connect to the other.  I have seen threads , and solutions, for similar problems with Windows, but not for Linux.  Any halp or advice would be appreciated.  john d