Can someone confirm this?
I am running into a major issue where it seems Pro is omitting pairs of single quotes ('') in the display of the Definition Query in layer properties. Look at the attached image, and notice that at the location of the black arrow, no single quotes are visible.
The query clause should look like this (which is valid SQL):
(osm_covered IS NULL OR osm_covered IN ('','no'))
but instead reads like this:
(osm_covered IS NULL OR osm_covered IN (,'no'))
Hence, the query does not evaluate: if I click Verify the SQL expression is valid, the dialog displays an error stating the SQL is invalid. Note that with Clause Mode, I see the same issue, the consecutive single quotes are omitted and don't display in the Clause Mode display of the query.
The issue only seems to be limited to the dialog itself, because if I save the layer to *.lyrx layer file, and examine its contents using a text editor, the SQL Definition Query looks OK. Also, the layer properly displays in the map, which is only possible if internally in the layer object, the SQL is valid: