Using an eVary to count a click incrementally and pass this through Analytics

Hi all

Apologies if my question or descriptions are basic, I am relatively new to the world of Adobe Analytics

This is in relation to the mobile core SDK (app tracking).

Basically I am trying to use an eVar to count an interaction incrementally and pass this through to Adobe so I can see it in workspace. In this particular instance after a customer performs a search if they click the 'fetch more results' interaction then I would like to count how many times they click this interaction. I have set the eVar to expire after an event fires (the event being if they close the search). So, for instance, if a customer performs a search and then clicks the 'fetch more results' button 5 times and then closes the search (where an event fires and expires the eVar) I expect the counter to return 5 given the eVar has now expired. 

Unfortunately, after testing I am only seeing a count of 1.

The is the syntax I have provided is

if app.interation = page name|fetch more results|button|

AND

trackTask.interaction

AND

click.counter

the click.counter is the eVar that should be counting incrementally. 

This has been set up in the report suite under the conversion variables as a counter

The processing rule has also been created to overwrite value of the eVar if the context data click.counter is set.

Am I missing something in the syntax perhaps I need something more like click.counter+1 given I am only getting a value of 1.

Thanks all I hope that makes sense!