...and then it runs down the wall and in behind the 'solid ground' where it also doesn't dry out. Mr. HandyAndy - Really
It would probably help if you removed the row of paving bricks wot run alongside the wall. Ensure water can drain away through the surface under - perhaps excavate a wee bit - and then refill with coarse gravel, stopping an inch or so below paving level. Probably. Possibly. Maybe.