Why 3 minutes timer is more easier than 5 minutes timer?
It looks like your blitz rating has increased by more than 100 points since you started playing 3 minute games about a week ago. Your blitz rating was 970 on 1/12 and today it is 1104.
It is hard to tell if the pool of players on 3 minutes chess is overall weaker than the pool for 5 minutes chess on the basis of one player's results.
You should really play all 5 minute games this week to see if your rating drops back to where it was.
Why 3 minutes timer is more easier than 5 minutes timer?