Bug maybe already resolved? Sieve rule does not accept special use folder names

[Marc Roos]

Sieve rule fileinto Spam fails, while fileinto Junk succeeds


  mailbox Spam {
    special_use = \Junk
    auto = no
  }

dovecot-pigeonhole-2.2.36-3.el7_7.1.x86_64
dovecot-2.2.36-3.el7_7.1.x86_64
CentOS Linux release 7.7.1908 (Core