Ah-ha! I just found another couple threads that confirmed version 5.18.5 on my PW5 is indeed the new problem.
Sorry I didn't see those before making my post above. I only decided to check my FW version while I was composing that message, and then after posting, went further searching down the rabbit hole.
I'm getting my old Voyage back online from it's dead battery state and hopefully that'll do the trick!!! 🤞🏼