Reported by @gziolo in #20052

From #20052 (comment) :

when opening the link popover from the block toolbar, the popover is placed in the position relative to the toolbar rather than the selected text, it would be also great to keep the indicator for the selected text

From #20052 (comment) :

Steps to reproduce:

1. Enter Edit mode in the text block.
2. Selects text with arrow keys + shift.
3. Press shift + tab until focus reaches the block toolbar.
4. Use the right arrow key to focus the link button
5. Press enter or space to launch the link popover
6. Observe whether the link is positioned correctly.

Note: I have not yet been able to reproduce this.