I have a QN90a and I noticed that the local dimming menu options get mixed up (sometimes, not all the time) after turning the TV off then on again. It happens on all sources (PS5, Nvidia Shield, Youtube in-tv app), and i have local dimming set to "HIGH" for all sources.
When Correctly Working This is what I see
Local Dimming Menu Selection Low. - Dimmest Picture, raised blacks.
Local Dimming Menu Selection Standard. - Brightest overall picture, good blacks/highlights
Local Dimming Menu Selection High. - Slightly dimmer than standard overall, but best blacks and highlights.
When problem shows (after turning TV off and on)
Local Dimming Menu Selection Low. - Actually enables what appears to be "Standard" local dimming mode
Local Dimming Menu Selection Standard. - Seems similar to the working "Standard" mode, and indistinguishable from the "low" selection in the broken state.
Local Dimming Menu Selection High. - Actually enables what appears to be "Low" local dimming mode. Dimmest picture, and the poorest blacks/highlights.
Once I notice the problem, i hold down the power button until the TV resets and the NEO QLED logo appears. After this, local dimming works correctly again.
It seems this happens on quite a few different models as I learned the easy fix online from people that ran into the same problem. I notice the issue since I have my set always on local dimming "HIGH", but if i were to use "Standard" maybe I wouldn't notice the problem.
It seems like a software issue since the menu selection seems to activate the wrong mode when the problem occurs. The fix is easy, but it's annoying to have to reboot the TV constantly to fix the issue.
The newest firmware update doesn't fix the local dimming settings problem.
Has anyone noticed that Samsung support never responds to local dimming questions? There's a post above where someone asks about their settings not sticking, as well as asking about the dimensions of the base. Support answered the base question and completely ignored the dimming issue.
Sure feels like support isn't allowed to talk about problems with local dimming.