> Your analysis also looks correct for me, would you share a patch with
> result->flag = ALLISTRUE; -> result->flag |= ALLISTRUE; ?
>
This looks like oversight of [0]
[0] https://git.postgresql.org/cgit/postgresql.git/diff/contrib/pg_trgm/trgm_gist.c?id=911e7020
--
Best regards,
Kirill Reshke