Problem:

https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=255057

Solution:

  * Download DVD ISO.
  * # mdconfig -f %%FreeBSD%%-13.0-RELEASE-amd64-dvd1.iso
  * # mount_cd9660 /dev/mdX /media
  * copy contents to folder.
  * remove any files you don't want - in my case, all 32 bit binaries. I only run 64 bit code.
  * [[https://www.freebsd.org/cgi/man.cgi?query=mkisofs&sektion=8&manpath=freebsd-release-ports|mkisofs]] to create a new ISO file.
  * burn CD from this new, slightly smaller ISO file.

If you don't have mkisofs ...

# pkg install cdrtools