Lost

It started working a while later but now its at it again gibberish or low volume on voice track but ok on background tracks.

Some channels now have garbled/Gibberish audio when selected, was on previous version and still happening on 3.9.6. Obviously different encoding for these channels but wasn't happening before with them but today (about 4 months science last used) Also volume levels seem a bit low on other Free To Air channels. Any ideas as to a fix