[bump]

You mentioned quite a few. normal, every day things, then asked if we've seen this. I'm not sure which of the many things you mentioned you are asking about, but yep, all sounds like a usual walk in the park. As for phrase match imps exceeding exact match imps, this depends on the search term and how long tail you're going.

Sorry for slow reply, I've only just checked back after I bumped.

What I'm asking about specifically is a notification on the keyword that it is NOT showing ads, yet at the same time multiple impressions are shown for that keyword. This is only happening where (i) the keyword is a phrase match keyword and (ii) there is an identical exact match keyword. Have you seen this? I think it's a bug.

The tester takes your Phrase match keyword, converts it into an exact match search, tries to run the analyzer, and of course, your Exact match keyword fires.
It has to choose a Search phrase to test against, there are too many possibilities that could happen, and infinite variety of phrase matched searches, could match up.
So you're seeing a shortcoming of the testing tool, it only test the exact matched version of your Phrase keyword when it runs the test.

The data there, next to your Phrase keyword, are for the searches that did match your Phrase match, but not your Exact match.

So...

Keywords = [Blue Widgets], "Blue Widgets"
Tester tool for "Blue Widgets" is correctly says searches for 'blue widgets' are zero for Phrase keyword, because the Exact match triggers instead.
Imps and clicks reported under "Blue Widgets" Phrase match keyword are for past searches like 'Blue Widgets in a blender', 'I hate Blue Widgets', 'I'm voting for Blue Widgets for President'.

The tester defaults to running a check on the search for 'blue widgets', which yields an exact match.
You can't ask that overlay tool to show you if your Phrase match "Blue Widgets" shows for 'Blue Widgets Blender'.
But you can in the Ads Diagnostic and Preview tool.

Get it?
Overlay tester only tests keywords, Broad / Mod Broad / Phrase / Exact, against the stripped characters out from the Keyword to create the Search of interest to study with overlay tool.
:-)

Sorry again for slow reply, first time I've checked back here in over a week.

I had to read your explanation a few times before I got it, but I understand now. Thanks for the explanation!

You are most welcome. Once you put yourself in the tester's programmer shoes, you can see the challenge she faced. And now you're wearing high heels. :-)