I'm working with a live connection to an Azure Analysis Services instance and it seems to me that measures with BLANK values have unexpected behaviours.
This problem arises both using "Standard" and "Azure" connector.
When I put into a table, or other visual, descriptive fields and only blank measures all performs as expected.
When I put into a table, or other visual, numeric fields and a blank measures these show random values (often they are randomly choosen from a field on the same evaluation row).
For my tests I have created a measure as follows "blankmeasure := BLANK()", so I am sure it should not return any value.