Update on the armhf situation: While we have diagnosed the general cause of the issue and have multiple people able to reproduce it, XMRig has effectively given up on finding and fixing the specific code that causes it, saying that armhf devices aren't worth the effort. [1] Unless there is outside interest in this issue, it's unlikely that it will be fixed in the near future.
[1] https://github.com/xmrig/xmrig/issues/2895#issuecomment-1092452685
