Thank you for your reply Airmann,
I have watched a lot of A350 wing view landing videos and I agree it seems to be rare.
I also cannot work out the logic as they certainly do not deploy/retract with the other ground spoilers.
I have watched some A320 aileron/spoiler videos as well. This more clear as while the aileron/spoiler deploys later than the other ground spoilers (probably due to all gear needing to be on the ground), the aileron/spoiler is released back to aileron only mode at the same time as the other ground spoilers are retracted.
I am puzzled.
Regards
Ed