Hi,
It looks like External (advanced) alias is omitted in firewall rules.
I have found the same topic - https://forum.opnsense.org/index.php?topic=9086.0 (https://forum.opnsense.org/index.php?topic=9086.0)
Unfortunately the patch recommended in the answer doesn't work too this diagnostic "1 out of 1 hunks failed while patching etc/inc/legacy_bindings.inc"
P.S. I try to use an alias with External in Floating rule
Best regards, Valerii