Resource collection less resources

I just collected resources at my Town Hall, using the collect button under the resource management tab. My warehouse was substantially empty (crops/wood/iron/stone). I should have collected tens of thousands of each resource (left thm all day to accumulate) but seemed to collect none. I did not check the precollection levels but the post collection levels were less than 3000 in each category. This post collection level was clearly too low.

I am in war refuse so I did not lose the collections to robbery.

I have thought that previous collections were shy, but put it down to absent-mindedness.

Not sure where the bug is but I will pay more attention, next time I collect resources.