Just to be picky about one issue - the keypads are daisychained (technically). The chain starts at one keypad, has the main PCB in the middle and the second keypad at the other end. This is a daisychained RS485 network.
For correct operation both keypads need to be terminated and the main board needs no termination - which is how you have stated it is set up.
When using a data bus hub, you are still daisychianing the network, its just twice as long.
Good to see it is working for you now.
Mick