OK, the problem is solved.
If I set the proxy in the Wifi connection, Android says that the connection is limited. As soon as you put the same proxy but in transparent mode (not set in Android, but filter correctely by the router when Android try to connect to outside), the connection is fully established and the synchronization is immediately done.
Sorry for the noise.
I would appreciate if one day, you may remove the needed support to Android sync…
Thanks a lot
Why Opentasks instead of Android Tasks?
I got here from the Nextcloud client on Android, which has an option to sync calendar, etc. That option leads to installing DAVx5, which led to installing OpenTasks.
I didn’t find this in the FAQs, so let me ask, why can’t Android’s own Tasks app be used instead of installing a third-party app? In doing so, I didn’t get my existing Android tasks sync’d over to my Nextcloud server.
Thanks for your help.
why can’t Android’s own Tasks app be used instead of installing a third-party app?
Because Android doesn’t have a tasks app, nor a tasks storage.
Do you mean Google Tasks? It’s not related to Android and not open-source, but a closed Google app and there is no (documented) API, so other apps like DAVx⁵ can’t access it.
Does that help?
Yes, that explains it for me. Thank you for your help.