Why does my MacBook Pro accept a charge from some wall outlets but reject others?

Voltage, common, and (for three-pin connections) ground, and the mechanics of the socket itself.

A socket with weak contacts can allow the charger cant downward and out of contact.

In the US, the available socket testers will catch the most common wiring errors.

If the charger is working fine in various other outlets in the building and elsewhere, then the issue seems to be with the particular electrical outlet.

There are basic plug-wiring testing devices available in the US and various other places, and you can ask an electrician to check the electrical system, GFCI/RCD/RCCD protection if present, and the available voltage present at the outlet.

It may just be a bad electrical receptacle. Did you try both outlets on that "bad" wall receptacle? Maybe only one of the two outlets is bad on that wall receptacle.

Definitely agree with @MrHoffman that something with that electrical outlet is bad, either the receptacle itself or the wiring for that circuit.

Worn wall outlet is the likely cause. After many years usage, the little "pressure prongs" lose the ability to grip.

Battery swap performed nine months ago;

Did Apple do the battery replacement?