Description of problem: These commands should produce identical output but do not: $ findmnt --noheadings --real -o FSTYPE --tree | sort -u bpf ext2 selinuxfs xfs $ findmnt --noheadings --real -o FSTYPE --list | sort -u autofs binfmt_misc bpf cgroup cgroup2 configfs debugfs devpts devtmpfs ext2 fuse fusectl fuse.gvfsd-fuse hugetlbfs mqueue proc pstore rpc_pipefs securityfs selinuxfs sysfs tmpfs xfs These are clearly unequal. Furthermore, neither seems right: i.e. {bpf, selinuxfs} should be pseudo (not real) but regardless are output in both cases. Version-Release number of selected component (if applicable): 2.33.2-1.fc30
Fixed by upstream commits 21d93094d4c6c7fcecb54ccb612c84e1392239d9 and 0e36d7c2711ed9f7a1f2479d798e83769d07cbb3. Fedora package will be updated later. Thanks for your report!
... and commit 9db442e95482a8a2fe1006d49f6010bf8f7ac35b for selinuxfs.