Strange Behaviour - What am I missing

So expanding on Problem with ThingUpdated (Text Files), I’ve been experiencing strange behaviour and I’m out of ideas where to look.

My ‘Account Bridge’ is defined in a text file, with a parameter ‘accessmode’ set to ‘mixed’.
The initialisation of the handler gets the config and sets a class String variable to this parameter.
I stop openhab.
Delete tmp and cache.
Start openhab.
The thing initialises but the parameter is set to ‘local’
This happens every restart.

Now ‘local’ is a valid option.
At present I’ve changed my xml to text rather than options to eliminate that causing it.
Where is it getting ‘local’ from? If I’ve cleared the cache and tmp folders surely there is no previous reference to this?

I’m lost where to look, what can be causing it, why this parameter persists.
Just a thought… I’m using rr4dj persistence, does this cache parameters?
Oh and OH 2.5.12 btw, haven’t tested on 3.x yet