Hello Community 

We have 4 EAP225, 3 EAP660HD 3 EAP620HD, 

2 660HD are located on the third floor, 2 620HD and 1 620HD are located on the second floor and the remaining 4 225 and 1 620HD are deployed on the first floor

We experience that when a user connects to EAP 660HD on the third floor and then goes down to 1st floor that had 4 eap225 and 1 620HD we noticed that the connection is being established still at EAP620HD, not on the nearby EAP 225 even if the EAP beside the users, and when we try to connect it to near EAP SSID it requires still and PSK and local user account to input 

Also when a user  on the 1st floor connects via EAP 225 and then goes to 3 third floor that had 2 660HD the connection won't roam automatically the user needs to authenticate  again in the user portal 

How can we address this kind of roaming issue? do we need to put EAP 620HD above and replace all EAP225 so all deployed EAP are the same models?

we notice that might the EAP 225 is maybe not compatible with roaming in EAP 620HD above?