We've got a vertical type windlass. Pulls up the chain fine, but the rode is slipping on the gypsy/reel. Current rode is 1/2" conventional braid. Would changing to an 8-plait rode solve this?
Possibly, but it might be too dense to go thru the capstan. Windlasses can be finicky.
Maybe the line is just getting worn. Have you tried switching it end-to-end yet?
If all else fails, contact the manufacturer and get their line reccomendation.