It appears the issue is due to the "Use single page display mode" option. If you disable that, you won't encounter this problem. I'll try to see if I can figure out what is causing the gap to grow in size over time.
Thanks,
Mike
UPDATE:
I've found the issue - it will be fixed in version 3.1.1.
Thanks,
Mike
UPDATE:
I've found the issue - it will be fixed in version 3.1.1.