Many items stop responding after a while since upgrade to OH 4.3.4

Undoubtedly, yes. The introduction of Tado’s new authentication required a quick fix in OH Core #4632 but some users had issues which were resolved via OH Core #4686 but this caused lockups that were finally resolved via OH Core #4699. Note that there is still an unmerged PR for the Tado binding in order to integrate the full functionality of the merged OH Core PRs.