Q: Drive belt replaced but initially screeching, tightened, still occasional sqeak- settled with WD40 spray but sqeak has returned.

There is a technical bulletin to increase the belt tension from to 800nm for a new belt and 400nm for a used belt. All belts will stretch when first put on and run a couple months. This is why a new belt is tightened more than a used one. The belt you have is good, it only needs to loosen the top alternator bolt and pry out on the alternator to tighten the belt using a gauge to 400nm and tighten the bolt. You may want to have to take the car back to the mechanic to have them see what’s going on. If you would like an independent mechanic to come check the car, a certified mechanic from YourMechanic can come to your home or office to diagnose the noise and let you know what should be done.