I had exactly the same story on a big event with 12 sxt sq lite 2, it was awe full, i tried basically everything, for 5 hours, then i just moved to another brand then it worked...
I was also using CAPsMAN.
I am interested to know why that can happen
Because some vendors can deal with interference better than others.
I watched a YouTube video linked by Mikrotik. A "respected expert" talked all about frequencies and airtime and "when it's out of space, it's out of space."
I call B--lshit!
I have seen "UniF--k" crumble under the same sort of stress.
But an 8 year old Ruckus systems "cuts right through it."
"It ain't what you don't know that gets you into trouble. It's what you know for sure that just ain't so."