Is there a bypass ball valve open a bit so not getting full pump volume to the booms? Also a possibility is the flow adjustment on your closed center hydraulic pump could be set a little too low. Has this sprayer ever had enough pump pump volume for 10 gal at 15 mph? It could be to just speed up your product pump for this job.Was spraying 5 gallons/acre with no problems. We switched to 10 gallons/acre and we can’t keep enough pressure to keep all nozzles spraying properly unless you travel at excess speeds. Any ideas?