Nice RBA3 opens halfway

[JohnW]

Hi,

I've inherited a Nice Robus RBA3 gate opener on my new house that drives an approx 4m gate using rack and pinion mechanism. I'd appreciate the following advice with my problem:

SUMMARY: Gate opens full but closes in stages. Halfway first and then fully. When it closes, it only closes halfway and then you have to press the button, which reopens it at first and then again to close. I just want it to close fully. Sometimes it'll get stuck in a loop of closing to halfway then opening fully then closing to halfway until I intervene.

1. I've been through the manual and looked at Level 1 and Level 2 programming modes that could cause this. It is not a partial opening problem, to my knowledge as I've enabled this feature and tested it at the 0.5m setting. I can create a partial opening but it still does this.
2. I've tried a factory reset - the same still happens 
3. The beam is not being broken and there is no irregularity in the rack mechanism. There is no debris on the runner that the wheels move on too.

I'd appreciate any advice 

Thanks
John