Weatherlink has to accumulate 1 hour of data before it starts sending 1 hour rain to CWOP, and has to accumulate 24 hours of data before it starts sending 24 hour rain. This is because the console does not keep track of these values directly. So, if you close the bulletin window and reopen it, these accumulated values get reset, and you have to wait for the data to accumulate. They could initialize these accumulated values with archive data, but they don't.
Steve