Thomas,

If both hot and cold are running slow in that faucet but not the rest of
the house then it's likely that the water pressure is good to the faucet.
It's not likely that both cartridges have failed. After the cartidges, the
water is mixed together and sent out the spigot. There may be crud in this
section of pipe. Try this. Remove both cartridges. Takeoff the mesh screen
at the sigot, get compressed air ( a bike pump), and blow from the spigot
back to the cartidge bodies. Clean up the crud and put everything back
together.

Dave M.