We have a boolean attribute that is no longer showing the value on the list view when added as a column in classic (it works fine in Modern UX). The column is empty (blank). If we create a new boolean, it works
Release : Any
The display mapping for the attribute is no longer set up.
1. Go to Studio - Objects - pick the object - Attributes - Open the boolean attribute
2. Scroll down and note if the Display mappings are there. You should be seeing it to be Icon - Yellow Checkmark
If set to anything else than Icon, it will not correctly display
3. If not set, please set it and refresh the view