Easy answer: Classic. Classic. Classic.
There is very little functionality in the “new” App that anyone needs, though you should be able to bring up that App if needed (e.g., to control Samsung TVs or Appliances not compatible with the Classic App). There is still a bit too much functionality available in Classic (and peer support here is more familiar with Classic) that is missing from New.
More details if you wish to do a lot of reading is in this Topic and a few others: