Tags change a mp3 sample peak level?!

So just have a tagless mp3 that has a sample peak of 0db then add a tag to it & check both versions in a program like izotope rx9

it went from 0.00db to +0.72db!

Why are tags affecting sample peak levels?

Metadata has no impact on the audio.What if you run a new peak scan on the original file without adding the tags?

Well it looks like it does, like i said tagless audio thats at 0db sample peak stays at that..

Once the tags are added theres a peak increase. I just tested at 0db so it was easier to see by how much

Have you tried another program that knows how to deal with tagged files?
It looks like your program interprets the tag data as audio data.

Moved to #bug-reports:no-bugs