Thanks for your interest in Syncfusion products.
We have analyzed the reported query and we need few clarifications from your end.
1. Are you performing external filtering in grid by having the value selected from dropdown which is placed outside the grid?
2. Are you binding any external data to dropdown and thus filtering the grid data based on the value selected.
3. By “I have a drop-down list in one of the columns”, did you mean that you have bound a template column with dropdownlist?
4. Screenshot of the issue that you are facing
5. If possible, share an issue reproducible sample or hosted sample link for our reference
Ragavee U S.