2006 still required sockets that could reasonably be expected to supply equipment outdoors to be RCD protected. This was taken to mean all ground floor sockets, and by most, all sockets.
If it was me, I would be swapping the CU. Its crying out for RCD protection, and the one you have is tat!
If it was me, I would be swapping the CU. Its crying out for RCD protection, and the one you have is tat!