10:30 Upon inspection found the tipping bucket tube at soil.b was clogged with ill-defined organic matter.
Since the funnel was full, I tried to allow this water to be measured (post-rain), but only was able to get 2--3 tips to register. Also, this likely would have been an under-report since the funnel's capacity had been exceeded.
We have decided that checking for clogs should be a regular maintenance task.