In ArcPro 2.9.5 I have a python script tool in the new toolbox (.atbx) with validation that sets the filter.list.
The issue I am seeing is that the values in the list are all empty strings. The number of rows is correct but the values are all empty.
I've simplified my python code to just set ['test1', 'test'2'] as the filter.list and it shows up like the screenshot below. What could I possibly do differently here to make this work? I am going to try the old style toolbox.

