There might be something odd with combined display mode (at least):
Use combined display mode
Click an unread row to view the contents
Note the row doesn’t appear to get marked as read (or not unread), although the counters update, AJAX requests are sent, and a refresh shows the expected “read” state
if its specific to firefox reporting to mozilla to fix anything is likely to be useless. also marking stuff is basically DOM manipulation which has nothing to do with js strict mode. strange.
i’ll install firefox after weekend and take a look
Been running both side-by-side for a day or so, and no obvious (related) issues noticed so far. (Firefox 58, Ubuntu 17.10, mysql 14.14, php 5.5.38.)
The only thing I’ve noticed is the lack of feed icons on the strict version, but I’m blaming that on lack of cached images on the strict version due to them sharing the same database (I know, I know…)