Loading modified mp3?

Question

API

Hello everyone, I can not download and save the modified mp3.
If you download mp3 from VK and upload it back - everything is ok, but if you cut the same mp3 and upload it again, it gives an error -

error_code: 15,
error_msg: 'Access denied: filename is incorrect'

I noticed that when downloading, slightly different responses come in the audio property, when sending a post request to the download address, specifically:
Normal mp3

Информация о mp3… ,"orig_info_deferred":true,"orig_info":{"uid":28-------,"tag":"2a2-------","srv":813530}}

trimmed mp3

Информация о mp3… ,"orig_info_deferred":true,"vkaf":1}

How can I fix it?