Fortigate - FortiAP - Wireless

I have recently upgraded all of our boxes due to them being quite old, some of them previously on V4.

We have the following SiteA - FG100D (v5-b0762), 4 x FP221B (v5.2-b0265) SiteB - FG110C (v5-b0762), 3 x FP221B (v5.2-b0265), 2 x FP221C (v5.2-b0265) SiteC - FGT80C (v5-b0762), 2 x FP221C (v5.2-b0265) SiteD - FGT80C (v5-b0762)

We are now finding wireless devices struggling on the network, so a few questions.

Would there be any memory or network issues having Frequency, AP Handoff and Radio Resource Provision enabled?

Any reason why my fortigate is trying to set access point to US

Is there any problems with my current configuration?

FortiAP Profile:     edit "FAP221C-default"             config platform                 set type 221C             end         set ap-country US             config radio-1                 set band 802.11n,g-only                 set darrp enable                 set frequency-handoff enable                 set ap-handoff enable                 set vaps "IntWifi" "PubWifi"                 set channel "1" "2" "6" "7" "11"             end             config radio-2                 set band 802.11ac                 set channel-bonding 80MHz                 set darrp enable                 set frequency-handoff enable                 set ap-handoff enable                 set vaps "IntWifi" "PubWifi"                 set channel "36" "40" "44" "52" "56" "60" "100" "108" "149" "153" "157"             end

SSID: config wireless-controller vap     edit "PubWifi"         set vdom "root"         set ssid "CTS_Public"         set security wpa-personal         set encrypt TKIP-AES         set passphrase ENC     next     edit "IntWifi"         set vdom "root"         set ssid "CTWL"         set security wpa-personal         set encrypt TKIP-AES         set passphrase ENC     next end