hm, I´m afraid seven years later this bug is still (or again) up and running?
We have the exact same problem with RadGridView of Version 2016.2.503.40.
This is actually quite urgent, because we need the custom filter features and the form HAS TO BE TOPMOST, because its an excel addin and the form will "disappear" behind the excel window when clicking in a cell.
What can we do about this?
Thanks for any recommendation in advance