Wow, this seems to be quite common - I wonder why it happens? It's an odd kind of waking up for me - almost like being jet lagged.
I have a list of tediously soothing podcasts that I like to listen to - if I fall asleep, great; if not I get to hear the podcast. Might try the sleep stories though - I don't have Calm but I have Headspace, which has similar ones.
Finally got back to sleep about 6am today, only to be woken up by my DH's alarm at 6.30. He was intending to go to the gym, but sacked it off and is still asleep in bed 