If you want to try doing the zwave "replace" option here is a guide I made for it: [Guide] Updating Firmware and ZWave Replace
Otherwise it sounds like the device is still talking to the hub via the leak alerts from what you said, so the replace is probably not needed. It is possible the built in ZSE42 driver will never ask the device for the firmware version except at pairing, so that may never change. You could try switching to the community driver and doing a configure/refresh from that and I think that one will get a new version: [RELEASE] Zooz ZSE42 WATER LEAK XS SENSOR Driver
I checked over the code, it looks like you do a "Save Preferences" at the bottom, it should set a state variable queuedConfig: true (Make sure the settings are what you want before the next step). Once that is set, wake up the device and it should update the battery and firmware version.
