Are the speeds and routes consistent? I'm just guessing since I haven't seen this. In my experience, I've seen over 30 mpg on roads with speed limits at 65 or less. On the interstate, I generally see around 28 mpg. I haven't seen fuel mileage drop to 23 on the highway.
Looking at your distance traveled and driving time, it looks like you average speed was under 70 mph. Maybe it's something related to maintenance, air filter etc.
2018 Limited, gas, white on white, Uconnect Theater, tow package, ACC.