Unable to "mark as SPAM"

[8uk54nt0]

Unable to call action "mark as SPAM" from Modoboa web GUI when modoboa-amavis 1.5.1 installed.
'POST /quarantine/process/ => generated 95786 bytes in 182 msecs (HTTP/2.0 500)' in /var/log/uwsgi/app/modoboa_instance.log instead of (HTTP/2.0 200).
After downgrading to modoboa-amavis 1.5.0, everything works as expected.
Affects long-years running modoboa deployment and also freshly installed one.