Just a note..
I always write down when I change reservoirs and sets in my log book, even where I put my sets...
From doing that I was able to establish the problem with the flexilink plus sets, and also that my levels go up after every reservoir change, and it is necessary for me to reprime after 4 hours and again 24 hours later else I get unexplained highs.
If you do get unexplained high's it just enables you to find a pattern....I to am on the combo pump.
Best wishes...Sha x