When a user tries to 'Choose field' in the list view filter, the value resets to empty Also intermittently users will not be able to perform export and import functionality.
After an upgrade, sometimes bad data will be cached in the user's browser. There is no specific reason why this happens. But the issue is seen most often after an Instance upgrade.
The resolution for this issue is to clear the user's browser cache. As the issue is related to the bad caching in user's browser and is not reproducible from ServiceNow end, there is no resolution that can be applied to all the users at once.
Refer the below links to clear the browser cache in different browsers.