I have tested this and it is possible to select a value in the mobile app so was unable to reproduce the issue.
Below I have selected 2020 in the alternate state list box. The inherited states are 2019 and 2020.
Check that you have applied the alternate state to your list box and a chart
Ensure that the app is published
Refresh or restart your device and try again.
Now if you mean that '0' selections applied appears when making your default selection, this 'might' be a bug. If so, this may indeed required a support request to the Qlik Support desk to investigate in greater detail.
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