Last year I found a binder in my attic from the old homeowner. It had paint colors, appliance manuals, and even the wifi password for the security system. Felt like I won the lottery, lol. That binder saved me from so many headaches when the furnace acted up. I still think about how much time that person saved me.

Did you check the flare nuts on your service ports before you even started the vacuum? I had the same headache until I learned those factory nuts are often just hand tight. I take them off, clean the mating surfaces with a bit of refrigerant oil, and re-torque them with a wrench. It made a huge difference in getting a solid seal fast. That hour hold test can turn into a whole day of chasing tiny leaks if those ports are weeping from the start.

Yeah, and I'm over here still using the spray can stuff from 2019 (don't judge me). Holly_garcia has a point about the potato itself being a factor, but I finally tried avocado oil and it was a total game changer for crispiness.