Have you changed your profile for BOINC? Try Device Manager - Device Profiles and check your BOINC profiles for the "Connect to network about every X days" setting. If X is 0.1 - the default value - or close, then you could see BOINC only keeping one downloaded WU and the behavior you're seeing. Increasing that value will increase the number of WU's you have downloaded at any one time based on the estimated time they will take to run.

Observation: Could be an effect of the severe over estimation of Time To Complete for the Genome Comparison.... new once still arrive with 6:40 minutes but are done under 2. It's still causing depletion of the work queue on my machine. Any other in the buffer and things work normal.