There are some BBs that bypass the threads, but may not satisfy the carbon frame bike buyer..

to revert to square taper cranks.


back to blind guesses..
maybe the aluminum BB insert is separated from the CF .. partially.
by force used to remove the siezed part

the BB was installed dry , I suspect..

may have been a false bargain, and you have a bunch of components,
then need to buy a new frame..

2nd hand CF bikes seem to be problems somewhat often on these posts.

[OK, no problem = no reason to post, Re what is not happening]