Has anyone encountered a problem with specifically the 710G models having an annoying belt squeal?

We have replaced Idler pulley, Tensioner Pulley, Alternator is new due to failure, Have replaced the fan belt with a shorter tighter belt, and recently replaced the fan pulley which the grooves looked to be worn down square and glazed we were sure that this must be it but still have the noise!! It is only when the machine heats up then it never goes away.

Does anyone have a fix that they found for this besides what we have done??

Any info would help thanks!