Which version of Tableau are you using? And does this happen to all your dashboards/sheets or only on specific ones? What data source is the workbook connected to?
I am using Tableau 8.0.5, publishing to Tableau Online. This happens to many dashboards that use slider controls. My IOS Tableau Mobile software is current and the data source is a TDE data extract based on a SQL Server connection. We can't publish live sql server connections to Tableau Online. I have experienced this problem for years where some dashboards show null in the readout instead of the number being filtered (in self hosted Tableau Server environments in various implementations with several clients).
I thought I would ask if this goes on with others.
Was this issue ever resolved? I am experiencing the same behavior where I would like to resolve this issue immediately.