In edit_tag we have:

if 'perm_id' in kwargs:
    kwargs['perm_id'] = get_perm_id(kwargs['perm_id'], strict=True)
elif 'perm' in kwargs:
    if kwargs['perm'] is None:
        kwargs['perm_id'] = None
    else:
        kwargs['perm_id'] = get_perm_id(kwargs['perm'], strict=True)

The edit-tag command is passing perm_id.

I suspect these parallel options come from the unification of editTag and editTag2 a while back. This looks like an easy fix. I don't see why both can't handle the None value, which would effectively make these parameters aliases of one another.

Looks like this was introduced in #1945, so this affects 1.21 and 1.22

Commit 144e157 fixes this issue

Commit 4e46be9 fixes this issue