This does not give any new information.
What could (possibly) be more interesting is to examine the file accessed when the crash happens, and if there are concurrent access in another thread. If you are unable to do that yourself, there remains the possibility of exposing the core file to people that could (maybe) find something more, but it would also compromise all your Duplicati secrets. It’s awkward to do that without the expert having a proper contract.
Anyway, the test that you did using a VM seems to show that when using a clean OS install, the problem does not occur. I am unclear if you used a clean new target or not (you should have created a new target)
If this clean install in a VM has the same update level than your problematic setup (that is, if you have an up to date VM), this shows that your normal setup has something very special in it that is not compatible with Duplicati. This kind of problem is difficult to solve, and even more remotely.