One of SSID shows No Internet Connection on specific AP area

[aimannfaizz]

We have 2x main SSID as below:

[Ruckus] A-WiFi >> All good

[Ruckus] A-Guest >> Faced No Internet Issue on specific AP area

We have 2x R610 AP in that S&M department: 
Hostname: RuckusAP-23
Hostname: RuckusAP-44

FYI, we are using Ruckus Unleashed The issue details as below:
- In our S&M Department, we have 2x Ruckus R610 AP that broadcast SSID "[Ruckus] A-WiFi" & "[Ruckus] A-Guest"
- The [Ruckus] A-WiFi has no issue on Internet connection
- But the [Ruckus] A-Guest has "No Internet, Connected" issue on that department only
- We have checked the uplink switch port configuration, seems same with other R610 APs on other departments
- We have performed "ipconfig /flushdns", "ipconfig /release" & "ipconfig /renew" to force reconnect to [Ruckus] A-Guest
- After a few moments, the Internet connection seems got on that SSID but sometimes the same "No Internet" prompt appeared again
- We have tried fine tuning the channeling manually between RuckusAP-23 & RuckusAP-44 to prevent interference
- We also disable 5Ghz WiFi on RuckusAP-23 because both AP's location quite close between each other around 5-7 meters
- After monitoring for a few days, seems the issue still happen
- We are sure that the issue not from Guest VLAN because other department not faced that issue

Please advice on this