Multi Series charts conflicting behaviour

I created two questions, displayed as charts. Each question is based on the same set of joined tables. Question A plots the data against a date field , Question B plots against a second (different) date field.

I add Question A to a dashboard then add Question B to Question A to create a multi series - all good so far. However, if I first add Question B to a new dashboard then attempt to add Question A to it, Question A is not listed in the “Compatible” questions. I could understand if neither was available to each other but this is doing my head in…

A + B is okay
B + A not possible

Any thoughts where I am going wrong? (Metabase 35.3)

Hi @brianwilson
That sounds very similar to this: Multiple Series (Combine two questions)
To completely understand why this isn’t working, we would have to look at the query for each question and the fingerprint/analysis too, since something is likely different between them.
You would use the browser developer console to look at the requests, which should contain all the information.