DeDupe rules fail on Version 2.21+

I had reports of donations failing on a large CiviCRM site yesterday. We traced it to a problem with DeDupe rules. and this issue details exactly what we experienced: dev/core#2362 (closed)

The site was running CiviRules 2.21.

Disabling CiviRules solved the issue, downgrading to 2.20 was a temporary fix.

As the database has the 2.21 updates, this is not a long term solutions.

Today I hit the same error on 3 other sites. Downgrading fixed the dedupe issue, but now rules are not firing as we had updated to master to get the fix referenced in #117 (closed)

So we are now faced with dedupe failing or rules failing.

All sites are:

WordPress 5.4.4
php 7.3
CiviCRM 5.33.2