Hi there
I believe I've found a bug with D365 regarding date fields.
I'm currently facing an issue with duplicate detection where the rules match on Last Name and Birthday (same date only) with the Ignore Blank Values option checked on both. When the rule triggers on creation of a new record the duplicate detection dialog appears but does not show any records like so:

Despite the rule triggering, which means the rules themselves work, it looks like D365 failed to actually go and retrieve the records?
I've went on to do a bit of further testing by applying the same detection rules to other date fields such as Anniversary and Last On Hold Time. What is interesting is that Anniversary behaved just like Birthday while Last On Hold Time actually worked as intended and brought back results in the duplicate detection dialog...strange.
Upon further investigation I've noticed that Birthday and Anniversary have their behaviour property set as "Date Only" while Last On Hold Time is set as "User Local".
Why is this property causing an issue for duplicate detection?