Macbook Pro 2019 drains battery while totally shut down

I have a Macbook 2019, 16” updated with Tahoe 26.1. When I totally shut it down and put it away, it drains the battery about 5% a day. I have looked on many forums and tried many fixes, but nothing works. I only use it a few times a week for a few hours a day, and while plugged in. I put it away 7 days ago at 100% charge and booted it up this morning to a 68% battery. When I check the 10 day battery, it shows zero usage over that period of time. Yes, I’ve made sure it is completely shut down and not waking up (I disabled wake-up on open). Powernap is disabled. I’ve deleted “invisible scheduled events.” Bluetooth stays off and I disable Wifi before shutting down. My battery health shows “Normal,” but that won’t last long with it self-draining when not in use. I’m not sure which update produced this, but it appears to be Apple’s way of forcing an upgrade or battery replacement sooner than would be needed. Any suggestions I have not already tried would be welcome.