Merging two audio files (.wav) with acrossfade and getting audio crackling

i’m merging two audio files into 1 with a acrossfade filter.

Here is my acrossfade filter config: acrossfade=d=10:o=1:curve1=cbr:curve2=cbr;

The merge is working well for .mp3 files, but when one(or both) of the inputs is wav type, it results in a intense audio crackling in the overlap time.

Thanks for any help.

I’m using fluent-ffmpeg, but the command line should be it:

ffmpeg -i file1.wav file2.wav -filter_complex “acrossfade=d=10:o=1:curve1=log:curve2=log”

The log provided by fluent-ffmpeg is: SEE THE LOGS

Here are the input files: https://drive.google.com/file/d/1ypzTokhGarvzkzituj6UfjAymzULCmWx/view?usp=sharing