My wife has the s10+ it doesn't blinks when we makes call. Even if it the proximity sensor why would it be blinking all the time when I make calls? And it a color distortion when I'm on a colorful screen.
Do you know what proximity sensor does?
If I rememeber correctly, S10 models had that sensor around battery icon/percentage. If you have a headset connected(bluetooth or wired), the proximity sensor isn't activated
The proximity sensor detects when a user is holding the phone near their face during a call and turns off the display to prevent keypad presses and battery consumption from the display.
I too see this exact problem. It does not come when we make calls via Bluetooth. Only when making calls directly from phones.
Since you full screen bezel less display, may be we are seeing this. I'm hoping it is not an issue.