CONFIRMED: LG Smart TV Software Update Bricks Apple TV (all versions)

I have two televisions, both from LG -- one is a 42" and one a 55", both the same era and product line of WebOS-driven Smart TVs. The LG model numbers are 42LV5400, and the 55LV5400. 

The 42LV5400 is running (recently updated to) firmware version 05.00.24. The larger TV is running (and has not updated beyond) 05.00.14 

Recently, the smaller TV updated its firmware via download from LG. Immediately, one of the HDMI devices connected to it (an Apple TV) simply stopped syncing to the television (connected via totally infallible HDMI, of course).

I have spent most of tonight debugging this. I've tried all kinds of HDMI cables, swapping ports, 3 different models of Apple TV, etc. Then I got a bright idea. Plug the Apple TV into the bigger television! It worked. Upon deeper examination I discovered that the larger TV has NOT updated its firmware for some time, while the non-functional TV has the latest.

So, given that I moved all these devices around the various HDMI ports on both televisions, my inevitable conclusion is that the culprit is... drumroll.. the firmware. Their newer firmware release, firmware version 05.00.24, seemingly bricks Apple TVs -- perhaps a bug in their HDMI 2.0+ implementation. At any rate there is simply no way to make an Apple TV work on this television running the latest firmware.

So, tomorrow I really get my geek on and force-load an older version of the firmware onto the non-functioning TV in an attempt to prove my theory. In the meantime I emailed LG customer support, and to my dismay they replied, both confirming my theory and advising that they would make no attempt to address the problem.

Who thought it was a good idea to make consumer electronics software-driven, again? We are all perpetually beta testers.