Currently I didn't changed any configuration except of desribed on link mentioned above (help.ubnt.com...)
Please find current interfaces screenshot below:
Situation is as follows:
If client (laptop cell or etc) is actually connected to AP1 (eth2) everything is working fine.
In case client is connected to AP2 (because of coverage for example), interenet connection doesn't work (I mean clients coulld connect to AP2, but no internet connectivity).