UI freezed when exporting

When I export audios using export queue, the UI freezed and have no response

This issue can be reproduct by following ways:

  1. open Export Audio Mixdown Dialog;
  2. Select ‘Multi’ tab;
  3. Select at least 5 channel (channel should be many enough so that the Export Queue List Window can NOT display all)
  4. Use option for “inserts, sends, master, fxs”
  5. Click ‘add to queue’;
  6. Click ‘export’;
  7. Wait for seconds, Then drag the slide bar by mouse (I just want see the state of the bottom channels)
  8. Then UI Freezed , can not be cancel ,can not be closed(But the background worker thread is still working);

Cubase Version: 11.0.41
OS: windows 10