This looks a little bit like a variation on The Android app Back button does not return me to my search results but specific to the tags view.
Reproduction (app version 1.0.71):
- Select any site (say Meta) from the sidebar
- Switch to the tags view using the top bar
- Choose a tag, any tag (android-app is nice)
- optionaly refine your search with more terms
- Go to any question found, go back
- you end on the unfiltered tags view
- Go back again
- lucky you, your search is here