Same issue here. I got GS7 Edge with 64GB SanDisk SD card in it and after update to Poweramp v3 some of my audio files are corrupted in similar way. Every corrupted mp3 file have it's previous size but when I try to play it, every single music player shows only part of original lenght of the song. When I copy that file into computer same story happen. File just seems to be damaged. To be specific about issue, in Poweramp I'm able to skip that corrupted part where the song break and it play till the end. But other players shows only part of the song from beginning to the corruption point.