I am lucky enough to work from home... and so I constantly have my line in the water at Ember Island... and I can say that since I hit 300 fishing about, what, 1-2 weeks ago... CONSISTENTLY I get 2-3 chests for every 1 hour of fishing. I don't think I've ever had a day that I only got 1 chest in 1 hour... today I have been fishing about 3-5 hours and NO chest drop... not one.
Have we been hit with a stealth nerf to chest drop rates with fishing? I have a GM ticket open as well in case I am bugged or something... but this isn't RNG... if it is I am the most unlucky person on the planet at the moment.