imapsieve suddenly not working anymore

[Thomas Stein]

Hello one and all.

Dovecot version 2.3.7.1

I've configured imapsieve like 
https://wiki.dovecot.org/HowTo/AntispamWithSieve a while a go and it 
worked
for years now. Suddenly i noticed moving mails to the spamfolder does 
not trigger the report-spam.sieve
script anymore.

sieve-test gives:

  ~/.maildir/.Spam/cur $ sieve-test  
/usr/share/dovecot/sieve/report-spam.sieve 
1542388745.M99384P16720.meine-oma.de\,S\=8173\,W\=8373\:2\,S -D
sieve-test(himbeere): Debug: sieve: Pigeonhole version 0.5.7.1 
(db5c74be) initializing
sieve-test(himbeere): Debug: sieve: include: sieve_global is not set; it 
is currently not possible to include `:global' scripts.
sieve-test(himbeere): Debug: sieve: Sieve imapsieve plugin for 
Pigeonhole version 0.5.7.1 (db5c74be) loaded
sieve-test(himbeere): Debug: sieve: Sieve Extprograms plugin for 
Pigeonhole version 0.5.7.1 (db5c74be) loaded
debug: file storage: Using Sieve script path: 
/usr/share/dovecot/sieve/report-spam.sieve.
debug: file script: Opened script `report-spam' from 
`/usr/share/dovecot/sieve/report-spam.sieve'.
debug: Script binary /usr/share/dovecot/sieve/report-spam.svbin 
successfully loaded.
debug: binary save: not saving binary 
/usr/share/dovecot/sieve/report-spam.svbin, because it is already 
stored.
report-spam: error: the imapsieve extension cannot be used outside IMAP.
sieve-test(himbeere): Info: final result: failed; resolved with 
successful implicit keep
  ~/.maildir/.Spam/cur $

I'm not sure the "the imapsieve extension cannot be used outside IMAP" 
is the error already or thats only because
the sieve-test script.

Any ideas on that?
cheers, t.