There's a persistent bug in the AEOTEC multisensor settings/options page. Typing in a value in the interval boxes does not stick and gets modified by some number prior to saving.  However, if you scroll through the up/down buttons, the value sticks as saved.

This has been confirmed and is on the list of things to do. Enter a number in the box and press up or down arrow. That immediately triggers a command to the device with the value, if the device has a different value stored it will return that value - keep hitting up or down to get to the value you'd like. 

ok- as I said, I discovered the workaround, just posting for others to see and ensure it's in the queue.