[BUG] Firefox BlockTypeSelect does not set 'focus' correctly.

[cdavies4]

• [Y] I have searched for similar issues in both open and closed tickets and cannot find a duplicate.
• [Y] I have read the documentation and cannot find an answer.

Describe the bug
On Firefox using the BlockTypeSelect plugin incorrectly 'focuses' after a BlockType has been selected. This leads to text highlighting on hover as though the left mouse button is pressed down.

Reproduction
This is reproducible on the live demo https://mdxeditor.dev/editor/demo by selecting a BlockType from the modal. Once a block type is selected moving the mouse across the screen will highlight text even though the left mouse button is not pressed. This behaviour does not occur in Chrome or Edge.

Expected behavior
Once a BlockType has been selected hovering over text does not highlight it. This behaviour occurs in Chrome and Edge.

Screenshots
Chrome - Selected a block type and moved cursor down the page

Firefox - Selected a block type and moved cursor down the page

Desktop (please complete the following information):

• OS - Tested on Alma Linux and Windows
• Browser - Tested in Firefox, Chrome and Edge

[petyosi]

Happy to accept a PR - it's a legit bug, but Firefox is going down in market share and my priority list is quite long, so I'm unlikely to get to this soon.

[david10sing]

@cdavies4

Is this still an issue? I am on Firefox 125.0.2 (64-bit) and I cannot seem to replicate the issue as per above.