1. Client is not roaming. Does the active/passive scan happens after the association and client got the IP? In roaming , it will switch to the higher RSSI , if the SSID are the same and scan happen there. if the answer is yes , what is the interval.
2. WPA_supplicant conf, has 5 SSIDs, SSID1,SSID2, and SSID3. when the client boots up. SSID1 which has the higher priority is not available so it select the next higher priority which is SSID2. Now client is connected in the SSID2 and working fine. Now if the SSID1 AP, comes back whether client will connect back to the SSID1?