Bug with add/delete row/column button in the tables

[Sindo]

Steps to reproduce

1. Create a table on an IP Boards forum
2. Trying to add/delete a row/column using the specific buttons which appear on the browser

Expected result

Those buttons should be on the borders of the selected cell

Actual result

Those buttons are very far from the table, in the top part of the page (see the attached file)

Other details (browser, OS, CKEditor version, installed plugins)

This problem is only with Firefox, because with Chrome and IE those buttons don't appear at all.

Can you please check this problem and let me know how can I solve it ?

Thanks,

Matteo Sindona

[Sindo]

Here you can see the wrong positions of those buttons, very far from the selecte cell.

[Jakub Ś]

DUP of #13269. Please also see ​#12449

NOTE: Setting config.disableNativeTableHandles = true; should hide them.