I did a Slow Ring update a few days ago and experienced the same. Soft reboot did not fix the issue. I had other issues as well including no messaging notifications. I went through the 950, exploring every menu option, resetting some and rebooting a few times as well. Finally, the 950 seems to have settled down with the new OS and all is well with the best battery life I've had so far! Also, I use Calendar + Pro live tile as it displays next 3 appointments.
Check your settings...reboot...and see what happens.