With 3.9.7, you shouldn't need that Ignores... property, but if you still do let me know. 3.9.7 fixed a similar problem in MinimalX so I thought it'd also fix your theme.
Thank you for clarifying. If we add an ellipsis to truncate the string, would it still need to scroll?
Yes, that is correct. Resetting on each selection would be a workaround. I will have to try it; my initial concern is it would slowdown the list too much but would have to try it.