SPP took to long to respond.

Hello guys, 

We have customer that use the SPP appliance on the version 6.0.12. The clients connect to customer over the Remote Access VPN connection (CiscoAnyConnect) and try to access to SPP portal. When the user write down the SPP address (DNS name or IP address > https://appliance.domainname.com or htps://10.10.10.10) the user firs time receive the message that "appliance.domainanme.com" took to long to respond. If the user wait around 20-30 second the page automatically loaded.

This always happen if the user try to open page with Chromium based browsers (Google Chrome, Edge,...). If the user try the same with Firefox the page loaded without any problem.

Maybe someone already have such problems and know the solution?

Best regards, Peter