Moen M-PRESS Chrome Two-Handle Metering Lavatory Faucet

Our school district recently renovated all 58+ facilities. We specified Moen because of the durability and warranty. About 80% of our buildings have the Moen 8886 metering faucets. After approx. 1 year we started receiving work orders for faucet not staying on after the handle was pressed. Over the past year we have replaced close to a hundred cartridges. We have attempted everything under the sun to repair cartridge in the field, more grease, less grease, stretch spring etc. Please keep in mind these faucets are only about 2 years old. Thankfully the Moen rep did send us repair parts but offered no solution to a field repair so we didn't have to replace. We have saved all the cartridges and handles that have been replaced in hopes to send to engineering department to offer a solution. No one has responded to our request for repair, they just send 50 cartridges at a time. The new cartridges fail after a certain period as well. We can not be the only purchasers that is having this problem. We just want answers, mainly a field repair. It has to be a flaw in the design. We have 3 new schools 1 being a high school being built in the next year and we may ask to spec a different faucet if not resolved.