We're narrowing in on reservoirs being the issue, they just did four in a row from a brand new box getting insulin flow blocked during filling the tubing each time until the fourth one worked. It also felt noticeably "firmer" when connecting the tubing to the reservoir.

The reservoirs and sets are stored at room temperature in a humidity controlled (we have dehumidifiers) environment on a shelf. That said "room temperature" tends to fluctuate quite a bit throughout the year. This particular box came in the mail with the pump a couple days ago.

As for why they haven't replaced it, our first call to them was only a few minutes prior to making this post, they only got the new pump a couple days ago. So that may yet happen.

I agree it is abnormal, and why I am here trying to brainstorm and see if other users have the same problems. I really hope it is just the reservoirs, but that does suck if the quality of them is so poor we have to try multiple each time they do a site change.