quote removal issues within character class

[Oğuz]

v=foo
echo ${v#[[:"lower":]]}

should print oo, but it prints foo instead. This is reproducible on bash
>4.4

Plus

case foo in (*[![:"lower":]]*) echo bar; esac

prints bar, while

case foo in (*[![":lower":]]*) echo bar; esac

doesn't print anything. And this is only reproducible on bash >5.0