Unable to update calendars after migrating to iCloud+ on iPhone
Before migrating everything to iCloud+, I had multiple calendars (Gmail, Exchange, iCloud) on my iPhone and Mac. When I was updated one event in one calendar, it was automatically changed on the other device.
After migrating everything to iCloud+ on my iPhone, I just have the Exchange calendar that still works. The others (Gmail, iCloud) calendars shows "unable to update calendars" on my iPhone (even if everything works on my Mac). I have updated my iPhone OS to the most recent one.