つまらないことに

over trivial things

→ つまらない
phrase Rare #42,169
over trivial things Used to describe directing time, energy, attention, or emotions toward things that are unimportant or not worthwhile. つまらぬことに is a more literary variant.
JA: つまらないことに腹を立てないで。
EN: Don't get angry over trivial things.

つまらないことに時間を無駄に過ごす

Don't waste your time on trivial things.

つまらないことに時間を浪費する

Don’t waste your time on trivial things.

つまらないことに時間を費やす

Don’t waste your time on trivial things.