With LanguageTool browser plugin enabled pressing `tab` when editing MediaWiki wikis doesn't go to the summary

[Faalagorn]

I do a lot of wiki editing, and normally when editing a MediaWiki-based wiki, pressing tab goes to the "Edit summary" field. However, when LanguageTool is enabled, that behavior changes; for example, on English Wikipedia it goes to "Insert".

I observed this on pzwiki.net and en.wikipedia.org, but it's probably present on other wikis using the built-in MediaWiki source editor as well (it seems it's not an issue with visual editing and FANDOM source editor)

I didn't test all the combinations, but it seems the issue is the same no matter what skin is used (observed on Vector 2022, Vector 2010 and the Citizen skin used by default on pzwiki.net)

To see the issue on Wikipedia without logging in:

• Go to https://en.wikipedia.org/w/index.php?title=User:Faalagorn&action=edit (or any other editable page).
• Choose "Start editing".
• Press tab.

Depending on whether the LanguageTool plugin is installed and enabled, either "Insert" or "Edit summary" will be highlighted. Disabling LanguageTool via the "Enable LanguageTool" switch and refreshing the page changes the behavior.

on pzwiki.net, since I don't have that toolbar, it goes to "PZwiki:Copyrights" link instead.

The tab should go to the next field where the data goes, instead of the link. Eventually, with enough tab presses, it will finally go to the field, but it's last in the line.

I'm using Firefox plugin on Linux, but the issue seems to be present in Chrome and Windows as well, observed by different users.