Distortion with FLAC file

Hello everyone, im exporting some FLAC files and im having an issue. I have some distortion going on but its just when i use this format (i used WAV and MP3 for the same song and got no problems)
Specificly the project is:
-The song with the mastering chain (and limiter) in one track and
-Intro/outro which is made of two tracks that goes to a bus, nothing of this goes further -9db.
Everything, the song and the bus, goes to the mix chanel (everything in 0 here).
Im working in a 48k 32float session. When i export  i use 44k1 32float plus FLAC 24bit

When i export the song + the intro, you can see that in the first 5 seconds there are some peaks that are above 0db and i would understand the distortion

Now if i export just the song without the intro the wave looks like this, nothing goes above 0 furthermore nothing goes -1 (i set the limiter of the song in -1db)

Something very similar happens at the end of the song where the outro apears (is the same track as the intro) there are some peaks that are above 0db

Any idea of where this could be coming from?
Thanks for the help!