@kautuk_sahni no, none of the suggestions so far have addressed the issue.

Yes, we have raised numerous tickets for this issue, but Adobe has not been able to provide a solution so far.Yes, restoring from backup (obviously) works, but is not a viable long term solution.

There is no heap error before this error. We use 4GB max heap, 4 cores.

We can track our changes and we did not make any unusual changes before it happened. Just normal content changes. This is our stage environment (out of dev --> stage -> prod).