No valid field to filter on in question from model

I can't apply a dashboard filter to all questions that come from the same model.

Replicate

  1. Model from native SQL query, with two dimensions where at least one is mapped field (e.g. City and Product) and two numeric fields to use as a denominator and numerator (e.g. Shipped and Sold quantity).
  2. 1st question, with custom calculation SUM([Sold]) / SUM([Shipped]).
  3. 2nd question, same custom calculation grouped by a dimension (Product) and filtered by the custom calculation (< 0.5) and sorted by the custom calculation.
  4. Add both to dashboard and add a filter on the mapped dimension (City).
  5. The filter can only be applied to the 1st question not the second.