Ouch! Not only is the major version end of life, but that's not even the latest revision of 11. At this point, you should use logical replication to migrate from your v11 to a shiny new Postgres v18 on your RHEL9 box. As Chris pointed out, the indexes are a libc problem, but your bigger problem is being on v11.15. If you want to trade complexity for time, you could consider using pg_dump to do the upgrade instead of logical replication.
