From my '16 manual:
If the check fuel cap warning light illuminates, the fuel-filler cap may not be properly installed. If the warning light illuminates, park your vehicle safely off the right-of-way, remove the fuel-filler cap and reinstall it correctly. After the cap has been correctly installed, the fuel cap warning light may continue to illuminate until a number of driving cycles have been completed. A drive cycle consists of starting the engine (after four or more hours with the engine off) and driving the vehicle on city and highway roads. Continuing to drive with the check fuel cap warning light illuminated could cause the check engine light to illuminate as well.
I assume your '19 is similar. The surprise for me is the 4 hours off requirement for the drive cycle.
Just to wrap this up, my CEL finally shut off by itself today (Wednesday).
To synopsize:
-My 2019 manual makes no mention of the CEL turning off by itself.
-It came on Saturday night, and I discovered the gas cap was completely off and just laying behind the door. I replaced it.
--I had gone through 3/4 of a tank of gas in the 10 days since I last filled up, so the CEL was horribly delayed.
-I've driven the car every day since, sometimes making multiple stops in a single trip. The CEL never went out.
-I stopped by a local shop I know yesterday and the guy's OBD2 reader has not been updated for the 2019 model year cars ("Needs Different Cable" message.) He told me he did not think the CEL would self-extinguish.
-I drove in to town this afternoon and made a stop, then I drove a few blocks to where I had a meeting. The CEL was still on.
--The meeting lasted 2 hours, I came out, started the car, and the CEL was off.
-I made a short hop to the grocery store on the way home, and the CEL has remained off.
I corrected a prior post where I stated you could not close the door with the cap off...the cap is not tethered as my truck's cap is. You
can (I obviously did) just lay the cap in the recess and close the door. Serves me right for not using the holder inside the door (which would have prevented the door from closing.)
This upside is this got me off my butt and I ordered an OBD-II Bluetooth adapter, along with a tablet to set up for diagnostics/extended gauges/Android Auto. I've chosen the OBD2 software I'll install. I'll post in Infotainment when I figure out where to put the tablet.