"Operation failed" when syncing a newly created task on CalDav (Disroot)

[VanackSabbadium]

Hi, first of all, great work, so keep up!

I'm using tw_caldav_sync to sync my tasks between a Disroot calendar and my local taskwarrior instance.

Creating a new task in my Disroot calendar and syncing with my local instance works correctly.
Viceversa, creating a new task in my local taskwarrior instance and syncing with my Disroot calendar does not work, even if it says "Caldav -> Items created: 1".
The error is: [caldav Insert an item using the given side helper] Operation failed. (as you can see in this screenshot)

I'm actually good because my main objective is to create tasks with my tasks app on my Android phone and then sync with my local instance on my pc, but i'd like to solve this issue if i'll ever need to do the other process.

Thanks for your help.