Data not showing after navigation back to the previous tab

This is probably because you are returning POSITION_NONE in getItemPosition which is

Called when the host view is attempting to determine if an item’s position has changed. Returns POSITION_UNCHANGED if the position of the given item has not changed or POSITION_NONE if the item is no longer present in the adapter.

from https://developer.android.com/reference/androidx/viewpager/widget/PagerAdapter#getItemPosition(java.lang.Object)

So Remove the override of getItemPosition you don’t need this normally.

Because you are indicating that the current instance of each Fragment is no longer in the list of Fragments it will be cause the Fragment to be re-created each time you visit the Tab that holds it.