New tele has 'rings' - advice, please!

vale

it's just a compressed concentric waveform pattern due to a lower bit rate than your tv is deisgned for.

imagine a 2D straight undulating waveform line, then bracket sections off (each wave ring) to a single average value for that ring or wave (lowest to highest point, or cycle)
then apply that to each wave radiating out from a centre point (in your case, brightest to darkest points of an image).

if you take the max brightness point (centre point) of the image to be 100% and the lowest point (outermost ring) to be 0%, then for the innermost ring or band flowing out from the centre, imagine that all brightness values within that range (between 100% and 90%) will be averaged out to 95%.
& so on.
so for the next ring or band, all values between between 90% and 80% will be averaged out to 85%.

so instead of getting a smooth transition between 100%-0% brightness to darkness (radiating out from centre point of max brightness), you get ten stepped or bracketed average values (95%, 85%, 75%, etc)

yout tv isn't broken & i think any compensating algorithm that tried to smooth over that transition ridge between average value rings would make things look virtual reality smooth, not natural.

strtdv

Isn't counting them how you tell the age of it?

ToneControl

it definitely looks like a compression artefact

It's worth playing with the noise reduction and sharpness settings on your TV though
the presets are often vicious, especially the ultra-bright, high-colour, high-contrast ones they use on display models in the shop