Major oil leak after oil change

If the oil loss started after oil change check to see if your oil filter is not all the way tight. My oil light came on a couple months ago about a month after oil change. I reached under my truck and could turn the oil filter by hand. Just something to check. Make sure the oil filter is tight and drain plug is not wet may leak at drain plug. Those are the cheep fixes.
https://forums.edmunds.com/discussion/50518/hyundai/sonata/oil-consumption-replace-your-pcv-valve

https://www.hyundai-forums.com/threads/2012-sonata-using-1-2-3-4-quart-oil-weekly-help.646107/

https://www.hyundai-forums.com/threads/11-sonata-using-oil.407386/

https://topclassactions.com/lawsuit-settlements/lawsuit-news/55863-class-action-hyundai-failed-disclose-sonata-engine-defect/

5W30 maybe synthetic your choice, filter Fram XG9688 or equivalent , 5.81 US quarts of oil.
link below may help, press the helpful button
Oil Filter Change Hyundai Sonata 2011 SE 2 0T Turbo

Changing the oil in a Hyundai Sonata is an easy task that should be performed every 3,000 miles. Follo the below steps to change the oil on your Hyundai Sonata:
1) Ensure the car is parked on a flat surface. Place a drain pan under the engine. Locate the oil pan directly under the engine. The oil pan will be at the very bottom. Now, unscrew the drain plug at the front of the oil pan with a socket wrench. Allow all the oil to drain out into the oil pan. Tighten the drain plug back into the oil pan with a socket wrench.
2) Locate the oil filter in front of the engine. There will be a cut-out in the protective shield where the oil filter is located. Unscrew the oil filter with a strap wrench. Allow the oil to drain into the oil pan. Place the old filter in with the waste oil.
3) Fill the oil filter with fresh engine oil. Screw the filter on to the filter housing by hand. Do not wrench tighten, which could strip the threads of the filter or filter housing. Open the hood for access to the engine compartment. Unscrew the oil cap on the top of the engine.
4) Pour in three quarts of engine oil. Pull the engine oil dipstick out of the dipstick tube and wipe it clean. Push the dipstick back into the dipstick tube. Pull back out and look at the engine oil level. If the oil on the dipstick does not stop between the two marks on the dipstick, pour in a half quart of oil and check the level again. Do not overfill.
5) Start the car and allow it to run for few minutes. Turn the car off and check the oil level once again. Add another half quart of oil if necessary. Ensure the oil cap is back on the engine and the hood is closed. Hope this helps and if you need any parts for your sonata, this site looks like it has cheap prices, free shipping and great reviews http://www.buyautoparts.com/carmodels/Hyundai/Sonata.html

Watch this video and I show you exactly what the owners manual says.

well the ring should stay on the oil filter if there was one on there when you took off the old one it came off and dont need it

THE RECOMMENED OIL CHANGE IS EVERY 3,000 MILES FOR MAX ENGINE LIFE, USE 5W-30W, ANY MAJOR BRAND LIKE CASTROL OR PENNSOIL WILL DO.

Could it be the rear main seal? Some times oil can be "blown" around in bell housing from fly wheel. If you can pry the inspection plate with a little regular screw driver and oil starts to come out its a good chance its the rear main

I finally figured this out. I was putting the o-ring on incorrectly. I actually had two o-rings installed.
The o-ring should not be visible when it is tightened down. The plastic should be touching the metal housing. The o-ring sits inside the housing, right above the threads, but not at the top. Two pictures attached.

I would talk to the tech where you had the oil changed to be certain even though it doesn't sound serious from your description.

10w-30w or 5w-30w depending were you live, in a hot climate go with 10w-30w, any major brand, don't use any higher viscosity oil, modern engines are designed for lighter oils to improve fuel mileage and increase bearing life. I like Valvoline or Castrol, if you plan to own the car a long time then synthetic oil really prolongs engine life.