One way to check for parasitic draw is using a multi-meter and checking every fuse individually. Also, I wouldn't rule out the starter either as this can go bad as well. It happened to my '14 QX80, starting around late 2020-summer 2021. Similar scenario where the truck didn't turn over as fast but more so times when I would try to use remote start. Sometimes it started and other times nothing would happen. After diagnosing what I could with my Autel, it ended up being a failing starter. Since changing it, I've got close to 30K miles and no starting issues.