hi,
I just finished to run your app in proxmox/debian/docker … I seems to work very fine !
Many thanks !!! 
I’m trying to use caldav … 
mac / calendar : I can connect to the URL,
- I can see it on the left’s windows. But I can do nothing
ios iphone or ipad : I can connect to the URL,
- It appears in the calendar ; I can put a new meeting in that calendar : it appears a few seconds in the ios calendar and disappears … I don’t know where
- it appears in the reminder with a the strange name QSDFKJ23409 (??? out of nowhere ???) ; i can add a reminder on that calendar ; i appears a few seconds in the ios reminder, disappears and appears in the vikunja’s tasks
- when I have a task in another calendar, I can’t switch it to our calendar !
a calendar in a selfhosted mailcow (mailcow.email)/SOGo : I can add the URL,
- the account appears … but I can’t add either task or event !
thunderbird : I can add the URL.
- I can fill a task in the adhoc windows in the right calendar but when I click ok, the tasks disappear.
- I can’t add an event
- I can’t switch a task from another calendar to the right one.
So, I’m a bit disappointed 
I read that it was not possible for now ? Anything new ?
Do you know a small client/server that could act between this two world ?