Raid tab is greyed out in the dungeon journal. Has been active since the pre-patch. Now you can’t click on it.
In the dropdown menu where you select which expansion you want to view, select Dragonflight.
It was a temporary bug it appears. When you choose dragon flight m+ from the drop down, it greys out the raid tab. For me, for a few days, that would leave it greyed out until swapping off m+ and back to regular dragonflight several times.