That is how the hash is calculated. It is a normal behaviour, especially due to how windows and Linux has different ways to calculate and show the size.
I think
@SILVANA357 may have a valid point here and maybe you should check it just in case.
Windows or Linux or Mac 1GB = 1GB and the exact size is set by the binary system (2 to the power of 30) and not the OS. The difference sometimes is that some software (regardless of the OS) calculates 1 GB = 1000 MB (wrong method) while others calculate 1GB = 1024 MB (right method).
Your torrent's exact size is 5.42 GB:
but the screenshot shows 5.8 GB
so even if we assume that is based on the wrong method (base 1000), if you try to solve for base 1024 you get 5.42 GB X 1024 = 5.55 GB while the screenshot shows 5.8 GB. There is still a difference in size. Even if you apply the reverse and assume that the 5.8 Gb is base 1000, if we do 5.8 GB / 1024 you should have 5.66 GB and not 5.42 GB which is the actual torrent size.
Just to make it clear, either the torrent should have been 5.66 GB but its 5.42, or the screenshot should show 5.55 GB but it shows 5.8 GB and there is about a 200 to 400 MB difference somewhere.
Not saying it's your fault or something, just trying to understand the oddity of the size difference. Maybe the screenshot is wrong?