If you are on the snapshots there will be a clearing of the cache every time you move to a new build.
I’ve never personally seen this issue when the Things and Items are stored in JSONDB instead of .things and .items files, even on OH 2. I’ve never seen it occur on OH 3 but I’m putting everything (rules too) into JSONDB at this point so probably wouldn’t have seen the problem anyway.
I guess something like 200 man hours have been spent trying to find a solution for it so far. It’s not that it’s acceptable, no one has found an acceptable solution despite trying. As rossko has said, this is a problem that has always existed and many many developers and maintainers have taken a shot at solving the problem.
It’s a work around for a problem/bug that has no other solution right not. It’s not by design. No one chose this approach. No one designed and implemented this. Through trial an error, largely by users here on this forum, the 2-3 restarts was found to work around the problem.
On OH 2.5 it’s probably not worth it. ON OH 3…
And for import/export/sharing on the forum:
If you do want to do this in OH 2.5, you need to install the Experimental Rules Engine and then a Rules item will appear in the PaperUI Menu. But PaperUI’s rules editor is mostly broken so I can’t recommend it. Though if you want to switch over to JavaScript or Jython or Groovy as your rules language I can’t recommend it enough. But you’ll still want to write your rules in text files. For Jython you can get started at [beta testers wanted!] Jython addon w/ helper libraries (requires OH 2.5.x).