The upstream author suggests that the issue may be related to the "H2 Database Engine" (Debian package: jameica-h2database) in a similar, but not identical case here: https://homebanking-hilfe.de/forum/topic.php?p=170111#real170111
Upstream H2 is at version 2.2.224, whereas Debian is at 1.4.197-7, which is approx. six years old. An update of jameica-h2database will likely fix this issue?
