I owned a 2019 Outback,and
I owned a 2019 Outback,and like so many others, the batt kept dying. My Subaru dealer in Monterey CA suggested I “keep the key fob in a steel container when parking near the house, or working in the garden, as it activates the computer whenever they are in close proximity to the car.
Their answer was to replace the battery several times over. After contacting Suburu National headquarters in NJ and getting no help from them, I decided to sell it back to the dealer for a considerable loss.
Apparently the battery is being drained whenever leaving the keys in your car while gardening, or even In your house while your sleeping!