My new 2020 SEL Plus does it. My MILs 2007 Camry does it. Cars will do that - the AC compressor is a pretty big draw from the engine power and it pulls the RPM down to a shaky zone. Seems like Hyundai should be able to reprogram the computer so that when the AC comes on, the idle increases or maintains whatever constant speed they want. It used to do it on older cars too. but they set the idle as low as possible to reduce fuel comsumption everywhere. I don't notice it all the time. I just let it be. it's under warranty til way after the lease runs out. If it gets bad enough I might bring it up to service folks. Or see if there is any idle adjustment screw to turn it up a tad.
OFF TOPIC _ What gets me is in my wife's 2020 Santa Fe, the engine cuts off at stops unless you disable that everytime you get in. I'm old enough and have been poor enough that you FEAR a car quitting at a stop sign and having to push it out of the road. Every time it stops I have that little worry in the back of mnind that it may not start again. LOL