I'm five months out and have had a few experiences like yours -- maybe three. In each case it has happened after I drank a wee bit too much of the alcohol that evening. Are you drinking or taking any kind of tranquilizer or muscle relaxant meds.? That could play into it. It happened to me early in the evening while I dozed on the recliner or during an afternoon nap, after a lunch with vino. Never during the night though.
So -- watch the alcohol and the general amount of liquid you consume toward the end of the day. It adds up and will overtax your bladder while you're dead asleep.
I'm sure it has something to do with your solid/liquid/ diet, but be sure to talk to your doctor about
Best to ya,