Just checking. I had this problem starting back in 2018 with my Outback 3.6R sold by Subaru of Glendale, CA. It began 6 months after leasing (and later purchasing) the car. I then had 6 subsequent and worsening recurrences until (thru a circuitous process I learned of here) contacted Subaru USA and and initiated the process to have the entire headunit/infotainment replaced. This was apparently done 28-Feb-24 (I should say apparently, since I can't say for sure what they did). 3 days later my car wouldn't turn over because battery was drained. I replaced 2 new batteries and the problem persisted. I brought the car in the SoG and they claimed not to observe the problem. Took the car home and next morning the battery was dead. And it was 100% consistent, but the exact time lapse is somewhere between 3 and 8 hours. Took the car back to SoG and again they said they couldn't observe the problem. I believe they lied. 3 weeks later they called and said they found the problem and they would have the part in ~2 weeks. I called after 2 weeks and they said they did not have the "part". When I asked what the part was they simply said the whole head-unit. The manufacturer (bizarrely) is in Syracuse, NY and they only send a repaired unit to SoG once they get a returned defective one. No ETA. My experience suggests that their behavior and the whole problem is being covered up. I have filed a complaint with the Attorney General here and am waiting for that to be reviewed and action taken against Subaru of Glendale.
I'm not sure if this applies to your issue but maybe this will help. I recently had an issue in December 2023 with my 2017 Outback 3.6 Touring where if the car was not driven for a couple of days, the battery was drained. After the technician performed diagnostics, it was determined the DCM (Data Communications Module) was drawing 3x as much power as it should. Once replaced it resolved the issue and as an extra benefit of the replacement, My 5G cell phone calls were clear again as the previous DCM only supported 3G and the DCM Gen2 supports 5G phone. See DCMs, Battery Settlements, and Dark Draws (Oh My!) and DCM bulletins updates and clarifications (15-318-24R and 15-317-24R). This chart may be helpful as well. DCM Generations.
