Dahdi-channels is not beeing updated

By editing the context in zap tech (via DAHDI compatibility) in extensions does not update /etc/asterisk/dahdi-channels.conf

I have to go manualy and edit this file in order for the context to take effect.
I have in chan_dahdi.conf the line
#include dahdi-channels.conf

How can I have the web interface on FreePBX to update context without having to manualy edit dahdi-channels.conf every time.

I have custom context installed.