WiFi Bandwidth

Hi

I have a Fortigate 200e with 1000/1000 internet speed and 4x  FortiAP 421e access points connected to the firewall. My LAN Speedtest returns ~800 - 1000 mbps which is fine but my wireless speed tests return ~50/100 and I believe this is the reason why my users are experiencing latency issues and dropped packets on the Wi-Fi with Zoom / Video conferencing calls. All video conferencing work fine on the LAN but just not so great on the Wi-Fi. 

I want to know if there is a way to increase bandwidth on my Wi-Fi or check to see if I have something misconfigured on the firewall that is limiting bandwidth. I did not see any traffic shapers configured and I am not sure what else to check. Firmware is up to date on all devices. we are only using 5 GHz

As a test , I connected a Ubiquiti U6-LR - WiFi 6 Long-Range AP to my firewall and speedtest returned same results to the client connected to the Ubiquiti so I believe its a setting on the Firewall that I am missing. 

Any help would be appreciated. 

Thanks