Server worker dies when generating spawnchunks

I've made a simple script in python that essentially runs server on and off in order to pregenerate large amount of terrain (file attached). In rare occasions server happen to throw "Server-Worker-N died" upon generating chunk, and crash. I couldn't find any similar bug already reported.

EDIT:

I've made some more tests and it appears to be really bug in java 11 and maybe not in jar itself.

After switching to runtime bundled with launcher crashes stopped.