As you have read the title, it's not about complaints against red tint but something new which i saw yesterday.
While browsing my phone in dark(minimum light conditions), i saw that the light which is emitted from our fingerprint scanner balanced the red tint and grey were all grey for a fraction of second.
Here's a explanation,
We all know that when we use under display fingerprints it light up the whole screen for a second and while i was trying to open my phone with wrong finger i saw that the screen lit up and the red tint was nowhere to be seen, greys were grey, it may be because of mixing of blue n red colour or the overlay which causes red tint to disappear. It might help the to solve this issue
p.s. i wasn't able to record the screen if you need a recording for it I'll try hard to record it