Sorry your bug report has been ignored by the team at Microsoft, Tomasz. You wrote a well-researched bug report.
As far as I can tell from my own testing (a few months ago) client-side scripts work with Bedrock Dedicated Server, but server-side scripts do not. It's not clear to me why this is the case (a bug? or not implemented?). I told myself I'd revisit the issue in 6-12 months and see if Microsoft had made any progress.
I wish you luck in finding a better place than this site to find support. The Discord chat is incomprehensible (to me). The other community forums are almost as bad. I believe, back when I was testing, that Reddit was the best place I could find for intelligible and compassionate support.
Thanks, Jacob. "screens" was a helpful tip.
I don't think I have a way to upload the world to any filesharing sites or anything from Xbox one with the stuff I have. Could also be laziness but yeah...
I actually did attempt to copy the world before but, alas, it also crashes in the same way
I've had the same issue. I've emailed support and have been told this is a known issue they're working on.
I was having this problem with a 20w16a --> 20w17a world. Appears that if I break the dirt blocks underneath the saplings (I've been breaking a 4x4 swath, just in case...), and then replacing the hole with the same dirt backs, the same saplings will grow. Seems to reset some property on the saplings and/or the dirt that's changed in the latest snapshot...