I think i’ve read msgs about this but I’ll ask anyway. Occasionally, when filling the Tandem cartridge I encounter stiff resistance when pressing the plunger. I have to try a couple times to find a soft spot in the little white pad.
Today, it was MUCH stiffer, and I had to try nearly half a dozen times to make it go into the cartridge at all. I was very reluctant to just push hard for fear I’d either wreck the needle or the cartridge or both. And I certainly didn’t want to wreck the cartridge because I don’t have spares and Medicare is snotty about how many they’ll let me have every 90 days!
What did I do wrong? What should I do differently next time?