I assume you have hardwired all the APs, otherwise that would be the first step. Make sure they're on different channels, and have narrow MHz bands (20Mhz for 2.4GHz, 40MHz for 5GHz) selected.
Only use 1,6,11 for 2.4GHz and don't use the DFS channels on 5GHz as they will regularly hang everything.
Afterwards you can try reducing the 5GHz transmission power so there is no/less overlap in the far rooms.
Unfortunately you probably need the 2.4GHz (at least I do) but as the range is so much higher it might make sense to deactivate it on some APs to prevent overlaps.
Doing this basically eliminated the issues for me.
I assume you have hardwired all the APs, otherwise that would be the first step. Make sure they're on different channels, and have narrow MHz bands (20Mhz for 2.4GHz, 40MHz for 5GHz) selected.
Only use 1,6,11 for 2.4GHz and don't use the DFS channels on 5GHz as they will regularly hang everything.
Afterwards you can try reducing the 5GHz transmission power so there is no/less overlap in the far rooms.
Unfortunately you probably need the 2.4GHz (at least I do) but as the range is so much higher it might make sense to deactivate it on some APs to prevent overlaps.
Doing this basically eliminated the issues for me.