We have all restarted routers and ps4's. We also have tried loading different in game content and get errors also. It seems unlikely that multiple players not on at the same time all have significant increases of multiple errors since the update. I myself have almost no errors ever until this update.
For GUITAR in particular, that can happen when there's a connection blip between fireteam members. So if you see that one a lot, you may want to recommend your fireteam to check connections. Do you know if you have any packet loss in your connection? What is your NAT type?
Nat 2 no packet loss