Inconsistent `~~` & `*` handling when both are combined, `~` is outside, and sandwitched by letters (`~~` is not processed)

[tats-u]

~~***a***~~

***~~a~~***

a~~***a***~~a

a***~~a~~***a

a~~a~~a

a

a

a~~a~~a

aaa

aaa

Only ~~ in a~~***a***~~a are not processed.