Google suites Google Workspace keep disconnect me
I have FortiGate 61E and we use Google suites Google Workspace for our office email, chat, etc.
We have wired issue that the Google Gmail, chat, etc. keep disconnect the users and they cant connect again, during that time all other sites will open with no issues! only Google work place including Gmail will stop working with the following error

We disabled all the UTM (WEB DNS SSL, IPS, etc. ) with no luck
We replaced the FortiGate with new one that dose not have UTM licenses with no luck.
We replaced the switch as will
We are using the FortiGuard DNS server, and we changed the DNS to 8.8.8.8 and 8.8.4.4 with no luck
its randomly happening
if we did not do anything will resolve itself within few min
Any suggestion
