Made a decision. The old AV amp doesn't do 4k video and @gabba agreed that it's over 13 years old too and was second hand when I bought it too.

So a new amp is under consideration. Let the research begin.

New AV Receiver procured. Now to move cables and cables and cables

14 years ago our smallest daughter was in high school and happy to be paid $50 to go under the house to run speaker wires for the rear surround speakers.

Now she's an IT professional and no amount of money I have so far offered can convince her to do it again for the new AV receiver.

I guess I'm going to have to do it myself when @gabba eventually complains about the wires running across the living room floor. She is soooo patient though