Updated Kali instance today and that appears fixed. PDF reports can be downloaded ok
However, also needed to create folder /var/lib/notus/products and make it owned by gvm as it was missing after the upgrade
Had similar issue to Database Migration from 21.04 -> 22.04
Needed to :
su postgres -
psql gvmd
DROP FUNCTION IF EXISTS hosts_contains(text,text) CASCADE;
DROP FUNCTION IF EXISTS max_hosts(text,text) CASCADE;
DROP FUNCTION IF EXISTS regexp(text,text) CASCADE;
before the gvmd database would migrate and openvas would start.