MAVIC Open Pro 622 15
This bike was ridden daily 30 miles per day for years. One morning the tire was flat after sitting through the night
I replaced the tube and inflated it. The next day it was flat again
I changed the tire and inspected the rim. There are no sharp edges. There are no protrusions. The puncture is on the inside of the tube towards the tape, about midway between spokes.
The tape covers the width properly.
Inflation has been per recommendations. The deflation has happened each time about 12 to 18 hours after inflating and not while being ridden

Help
Yes, I am ordering new rim tape even though the current is in good condition. I used bare hands to feel for shards / bumps, going both directions and from different angles