I plugged it into the older Samsung TV upstairs this morning and it worked after thinking for a while. At first it wouldn't play when I pressed the remote buttons. Eventually it did play and then I tried some other discs and it worked.
I have not attached it back to the LG C2 OLED TV I have here. In the evening I decided to just get a better player so I ordered a Panasonic DP-UB820-K that will arrive by 10pm tonight.
While at first I thought that the video from the DVD on the older unit wasn't as good, it slowly got better and I had the much blacker blacks that I'd expect from an OLED TV. So I just decided to replace the player with a better player.
I will likely plug the replaced player into the TV here just to see but we could use a player at our house in Maine for the summer so likely I'll save it for that.