Video Conferencing degradation

Users are experiencing intermittent video freezing and robotic audio during VC sessions (Zoom/Teams/Webex). Despite having 3x 100 Mbps Dedicated Internet Leased Lines (ILL) and SD-WAN rules in place, the traffic does not seem to be optimally prioritized and is getting errors as "your video is paused due to network problem"

Environment Details: FortiGate Model: FGT-400E

Firmware Version: 7.4.9 Link Setup: 3x 100 Mbps ILL via SD-WAN.

Current Config: Performance SLA is configured for Jitter/Loss.

SD-WAN Rule "Lowest Cost SLA with load balancing" is set for VC applications.

Traffic Shapers (High Priority) are applied to VC traffic