I’ll just describe here something that I encountered (probably a bug) and how I worked around it.
Background:
I run OH3.1 release build. I had flashed a zwave usb stick (zwave.me uzb) with latest firmware. After having restarted OH3, all earlier z-wave things showed up as dead so I deleted them. I then re-added all z-wave things and also created items for them. No problem there.
I have a page with cells that have Action items pointing to the no longer existing z-wave items. Obviously those cells didn’t work anymore (e.g., those with switch didn’t toggle state etc).
The problem:
I updated the cells so the Action item were correctly pointing to the newly created items. I could then toggle the switch states on off. But the states were never reflected in the page UI cells. I tried to update the Action items several times with same result (can toggle the switches on off but shown state in the page UI cells never change (instead of ‘ON’ or ‘OFF’ shown, a ‘-’ was shown).
The workaround:
I deleted the cells and created new ones with action item pointing to the correct items.
With that, the cells were able to toggle switch states and the states were reflected in the cells.