Puzzle rating is going down as puzzle tier increases?

As I'm climbing up the puzzle tiers, my puzzle rating is falling more than it is rising. How am I supposed to increase my rating now that the puzzles are getting harder due to higher tiers?

You always drop more points when you fail than you gain when you solve. Unless you are guessing moves in few seconds which is very bad idea if you want to actually benefit from solving puzzles. You just need patiently calculate every puzzle for several minutes until you are completely sure you figured out correct solution and climb by just 5 points.

GM Robert Cvek made very interesting point in his book. When solve any puzzle, before starting to calculate any line, he always asks himself “What is my opponent threatening?” Because this is exactly what you need to do before your every move in your games.

Tiers have no influence on the puzzle selection algorithm