Corrupt basefile or template?

Is it possible to have a corrupt basefile or template?

Our default template (yealink-default) has been causing issues. Phones which have this template assigned appear to take a long time to respond. They boot fine enough but the web interface and key strokes take forever to start working.

I’ve also noticed that if you make a change to the yealink-default template and rebuild the configs the changes don’t appear in the mac.cfg files if you grep for them. Changing to a different template and you see that grep shows those new settings. Change back to the default and the settings of the previous, working, template remain.

I’ve been changing the basefile for days screaming wondering why the changes weren’t kicking in, only to realise that no changes to that basefile were showing in mac.cfg. If I copy the template the issues remains in the new template/basefile. If I create a blank one and manually enter the changes then everything works perfectly.

Is there a way to recover from such a thing?
Olly