Fortinet Wifi Slow Speeds

Add another hair pulling situation to this fiasco of 1-on-1

We're running close to 300 Windows 10/11 acer spin B3's using Fortinet for our Wifi solution on 2 physical campuses.

I've updated firmware, adjusted radio signal, etc. and not really seeing any improvement. I've gotten with my ISP to check on their end, and we're getting close to 900mbps down at the modem.

The "contractor" that is in charge of managing this part of the network suggested we do only a 5g band on the student network SSID, which has helped, but I feel like it's not a complete solution.

This morning I got notice that the Faculty network is slow and sluggish...sure enough, running speed test on that SSID i'm getting 31 down and 28 up (huge difference).

Have any of you just set your whole network to 5g and dropped the 2.4 band?