Then it should be in a separate thread, please.
The issue this thread is about only affects copying/moving collections with sub-collections into other collections.
If your issue only happens when dragging into a zip, check it isn't due to antivirus blocking access to the zip for a long time while the zip is scanned.
Assuming it's not due to A/V, please start a new thread for it, and send us some snapshots of the freeze for investigation: Manually generating process snapshots
More detail on the exact sequence of events to trigger the freeze may also be useful (in a new thread).