2 out of 3 SSID's having difficulty been seen

Question

Hi,

I have 1x R500 with 200.5.10.0.291 setup as Unleashed mode.
So, i have 3 SSIDs active, and for some strange reason, only 1 is showing regularly, and the other 2 may of maynot pop up, and its very frustrating!
Each SSID has a different VLAN.
I have turned Scheduling on so they all turn off at night, and weekends, all have slightly different timings, but are close enough. 
Numbers are around 45, smartphones, laptops in total.

I have only 2 theorys as to what might be going on:

1) Their are Lots of AP's in the area, so may be some radio interfering issue?
2) I have started to notice that Android models Might have the problem, but still investigating.

Any ideas will be useful,
Thanks

unknown · Answer

Yes, this has been resolved. I also noticed a DNS entry was wrong so All clients has the wrong DNS, opps! Anyway modified DNS and Flash firmware solved the problem.

unknown · Answer

Just found this, and flashed it 1min ago: 200.6.10.1.310