Channel scan does not refresh groups(folders)

I did a initial scan which brought up all IPTV channels in their respective folders. Recently there has been some updates in the M3U file. Some groups were removed from M3U file and the channels have been moved to another group, But even after doing a rescan, the group information is not updated in the interface. I still see the deleted groups in the channel navigator. Is there any way to do a scan from scratch?