So I noticed some odd tooltip behavior when looking at this example:
https://www.bryntum.com/examples/grid/celltooltip/
If you start your cursor somewhere NOT over the grid when the page loads and then hover directly over the City cell that is empty, you will get an empty tooltip bubble instead of the tooltip not showing up at all.
Similarly if you hover over a cell that does have a tooltip, like something in the name column, and then move your mouse off the grid and wait for the tooltip to hide, and then mouse over the empty city cell again, it will show with the LAST tooltips value instead of not showing at all.
Hopefully that makes sense.
I'm on MacOS 10.14.6 on Chrome Version 80.0.3987.132 (Official Build) (64-bit)
Support Forum
Confirmed, ticket opened - we'll get this fixed: https://github.com/bryntum/support/issues/434
Thanks for reporting!
Thanks for reporting!