AAC files not playing gapless

[Tristia]

Due to my phone's storage limitations, I've been saving my flac files as QAAC encoded and re-saving them, and the files that should be gapless are playing with some gaps (or ticks/noise?).

I've tried re-encoding them using different commands and different AAC encoders, but the problem repeats itself. 

Strangely, when I convert them to ALAC or MP3 files, they play perfectly fine. Moreover, when I play those AAC files in Foobar on my desktop, they play gaplessly. 

Does anyone have any idea what the problem might be?