No, an appeal to authority as an appeal to their work or expertise is not an Appeal to Authority fallacy.

An appeal to authority fallacy is what you guys did implicitly in saying that a Ph.D. who believes something, etc., is acting dumber than their Ph.D.: turned around, you show that you expect that Ph.Ds are to be trusted simply on the strength of the Doctorate. They may have relevant knowledge or not, due to their Ph.D., or they may have knowledge outside of their Ph.D.

To make a point about a person's character is, also, not necessarily a fallacious item, an ad hominem argument.

It is clear in these cases that using expertise (which might agree with socially adored power or not) or talking of character (which might be true about the person or not) is fine if the appeal in each case is not outside their ARGUMENT.

A bartender can be an excellent witness on car mechanics if he knows the mechanics; a mechanic may be certified but be unnknowledgeable about some feature asked (or have been bought off to lie). To appeal to the latter only due to the certification, is the appeal to authority fallacy.