From the perspective of the controller there's no special config required. It seems that probably is a L2 or L3 issue on VLAN 2.
The only thing you need is that subnet on VLAN 2 is routed and be able to reach subnet on VLAN 1, and if firewall in the middle then allow ports needed.
If APs in VLAN 2 disconnects frequently, there could be a traffic issue. Scan VLAN 2 subnet to see if there is any abnormal non-desired traffic. You can also ping from VLAN 2 to VLAN 1 just to see if there's any intermittency to reach VLAN1 gateway.
Just some ideas.