You likely “lost” streets due to Random nodes showing as incomplete on completed roads - #7 by JamesChevalier and they’ll return as I process the data to correct things.
You don’t need to mark anything as manually complete. I’m unsure, offhand, if doing so will affect the reprocessing I’m doing 
so I’d definitely suggest that you don’t mark any more streets as complete. Depending on how many you marked, I might suggest you unmark them I’m pretty sure city syncs include a step that “corrects” this - effectively toggling them off ‘manual’ and properly associating the activity that completed the street.
Manually marking streets should behave exactly like when GPS completes them. It’s possible that there can be some delays while all the stats are calculated, though.