Forticlient SSL VPN and MS Teams

Hi

We are running a 3240C and have SSL VPN enabled for staff users to connect in with, most use the Forticlient but some also use the web interface of the VPN.  However we have noticed that whenever anyone is connected via the VPN then online calls and video meetings suffer really badly from jitters and poor voice.

I have gone through reducing memory overhead on the firewall and it's now running in flow mode.  Also have moved the policies for MS traffic to very near the top for internal and SSL users.

Forticlient version is 6.0.8.0261

Thanks for any help or advice

Ian