[MM3-users] hyperkitty won't list more than 5 posts and shows empty grey Activity Summary box

Hi,

On our new installation of Mailman 3, which seems to be otherwise working fine (thanks!), the "More..." link doesn't work, such that the list continues to only show 5 posts, even though it's clear that hyperkitty is aware of more (if I click on August, for example). Also, nothing is shown in the grey box under Activity Summary (the <svg class="chart-data"> element), although I'm not sure what's supposed to be shown there. The public archived list is here: http://seznami.cjvt.si/hyperkitty/list/test@seznami.cjvt.si/. I'd appreciate any pointers.

Regards,

Cyprian