How does this work (Insert Effects)?

Hi there. I am totally new working with this. Can somebody please explain this:
I have a drum track (audio) and a bass guitar track (audio). I made a Maximizer setting on the drumtrack (Drum Buss Enhancer preset) which made the drums sound great. I also wanted to use the Maximizer as an insert on my bass guitar track and after selecting the bass guitar track I picked (Light Dance Master preset) which made the bass guitar sound like I wanted it to sound.
Then I noticed the drums sounded different and I selected the drum track and to my surprise the Maximizer was changed from Drum Buss Enhancer to Light Dance Master, i.e. the bass guitar setting…
I always thought Insert FX’s are exclusively for the selected tracks (or group) only, so why does changing the Insert FX on one tracks affect the other track(s)?
What newbie mistake did I make?