I removed the lower front cover to better identify the source of the sound. Determined the part that needed replacing was sold out at many places but AppliancePartsPros.com had a part in stock (and also a helpful video on how to change it)!
The part was in hand two days later.
I changed the part and put everything all back together. Pressure tested and … no leaks!
The dishwasher is running like a champ again.