I'll add some data to this as well. My 2020 seems to be using a lot of Def as well:
3427 km (2129 Miles) - Added full Mopar Def Jug (Gauge was at half way mark)
6855 km (4259 Miles) - Added full Mopar Def Jug (Gauge was at half way mark)
8935 km (5552 Miles) - Added full Mopar Def Jug (Gauge was at half way mark)
So on average I'm getting roughly 3000 km (1864 Miles) per jug (which is 9.46L or 2.5 US Gal), estimate 6000km (3728 Miles) per tank. All non-towing at present.
When I do the math here, from your first addition at 2129 to your last at 5552 (3423 miles), you consumed 5 gallons of DEF.
In that 3423 miles, I'll estimate fuel consumption at roughly 207 gallons (assuming 16.5 MPG).
IF the above is somewhat accurate, your DEF consumption is approximately 2.42% of fuel consumption.
This appears in-line with industry expectations for DEF consumption (2% - 3% of fuel).
Disclaimer: Many assumptions were made for this calculation; without filling the DEF tank completely up each time (the gauge is not very accurate), it's impossible to know if the tank was "as full" after the final addition at 5552 miles as it was after filling at 2129. The above @$$umes it was.