Dynamic Values breaking on certain rows only

Hi folks,

I have a report that uses several text boxes with defined Dynamic Values to deliver information about rows of data from a single table. 

These have worked flawlessly across the board for the past several months, but recently I found there's at least one row of data they simply don't work on - the dynamic value returns the "no value" error symbol. The data is there; I can drop a table in the report with the same filtering and all the values show up. But the Dynamic Value queries just break - only on this one row. There are no query errors in my data and all other forms of reporting work fine on this row.

Compounding this challenge is the fact that there seems to be no formal documentation for this feature, and I can't find a way to troubleshoot by viewing the underlying query.

Appreciate any guidance on ideas for what might be breaking or ways to troubleshoot this rather opaque piece of functionality. Thank you!