@mib2berlin said in Reliable calendar provider with two-way sync and Android support:
On mobile I use OneCalendar it is synced with the Vivaldi calendar.
You mean "Vivaldi.net" calendar or Gmail?
Also, if you're saying there's been some pertinent debugging lately, can I download a beta that includes the improvements?
Does CalDav support bilateral sync and all the usual features you use in calendarin', or is it view-only?