This seems to apply to foxes too. Possibly other mobs. If a tamed wolf gets angry at a zombie or any other mob, it will attempt to attack the mob too far away to be able to attack. Wolves will often suddenly stop advancing their target and jump up in attempt to attack. During my testing in 1.13.2 wolves would stop advancing and jump when they are in clear attacking range of enemies. Something was changed in 1.14 that causes this buggy behavior that essentially makes wolves far less useful than they used to be.