This case fails since it is added in r351421.
This is almost certainly the result of the same i386 bpf issue as #239380.
A commit references this bug:
Date: Tue Sep 17 22:08:16 UTC 2019
New revision: 352462
Temporarily skip sys.netpfil.common.forward.pf_v4 on i386 CI as it always fails
Sponsored by: The FreeBSD Foundation
*** This bug has been marked as a duplicate of bug 239380 ***