extracthifi outputs a file with a size larger than the input file

Question

[yh1126]

After running extracthifi on a .bam file, the resulting output .bam file had greater size than the original input file. (42.73 GB -> 46.97 GB) Is this possible? By what I understand, extracthifi is supposed to only retain Q>=20 reads, so there is no reason the output file can be bigger than the input. Has something gone wrong?