FortiClient 6.2.6.737 not connecting to SSL VPN on OSx 10.15.4

I got a user using the FortiClient (6.2.6.737) on his Mac (OSx 10.15.4). He recently updated his Mac and is now unable to connect, to the SSL-VPN connection. The target device is an FortiGate 60E running FortiOS 6.0.8 build0303.

The FortiClient is already reinstalled and the login using the webclient works as expected. 

I also found the special notices article in the Fortinet Document Libary, but I didn't find two of the mentioned files called fcaptmon and fmon on the harddrive.

I already found FortiClient in the list for Full Disk Access and fctservctl was added from the harddrive under "Libary/Application Support/Fortinet/FortiClient/bin/".

I hope someone is able to help me and thanks already for your help.

bfo