Gallery shows some A+ content today, although disabled in my settings (it was tagged as such, but still shows)

Did you changed the settings from the filters at the top? Sometimes the rating is desync:

• You load the gallery, the picture is rated as M or A

• The moderator sees it, and changes it to A+

• 5 seconds after, you open the picture, and you see it as A+

But you've already loaded it … So that might what happened here