Article page keyboard traps

to reproduce:
theme=olh, article with some tables which have internal footnotes.

keyboard use. tab and enter to see larger table.
tab within table to an internal footnote index link - it correctly highlights the footnote within the modal, but focus is then changed to the main article while modal stay open, creating a keyboard trap.

Additional problems with tables with index in main article (not enlarged modal) - where after movign to the destination and highlighting, focus goes to top of page (the skip to main) rather than continuing from landing point.

On clean, the focus doesn't enter the table modal at all after opening.

So all in all, the issue here is "Get Keyboard Navigation working on Article Pages."

Start by reproducing the keyboard flows on an article with tables and internal footnotes under the olh theme, then compare them with the clean setup. Trace focus when opening the enlarged-table modal, activating an internal footnote, and returning from the destination; done means focus stays usable in the modal or continues from the landing point without jumping to the top or creating a trap.