The old Smart Things zigbee motion sensor is still in the ST shop, but now it’s called “original” instead of v1.
There are three things to know about repeaters.
Devices running on battery power don’t act as repeaters for either zigbee or zwave. Repeating would burn through the batteries too fast. The ST original motion sensor can act as a zigbee repeater, but only when it’s plugged in via
USB cable. If you use it on battery only, it won’t repeat.
you’re absolutely right: zigbee can only repeate zigbee. Zwave can only repeat zwave. Different antennas. And encrypted zwave messages (“security”) can only be repeated by encrypted zwave devices, which is where “supports security” matters.
this FAQ explains more:
And here’s the link to the original motion sensor in the store. I know the link looks weird, but it seems to work. (If it doesn’t, use the SHOP link on this page and look in the Motion category for the Original ST motion sensor.)