The synchronization does not work when a pane belongs to multiple groups #95
Description
First off, thank you for the nice library!
I have noticed what seems to be a bug: when a pane belongs to multiple groups and its scroll gets synchronized through one of these groups, then scrolling on it fails to synchronize the elements of its other groups.
This can be reproduced consistently on https://react-sync-scroll.netlify.app/#scrollsyncpane:
- scroll the blue table down
- then scroll the red table to the right
Expected: the black table header follows along and scrolls to the right.
Observed: the black table header remains still.
