Light yellow regions on the screen of my iPhone XR. Any suggestions/fix?

I

iMore Question

1. The regions cover almost 50% of the screen and are visible on a white background.
2. It's definitely not a software bug.
3. The phone has experienced some minor exposure to rain but it was not heavy rain and the duration of exposure was for a few seconds.
4. It's been almost a week and they are still there.
5. I checked the water damage indicator and it hasn't turned red.
6. I do live in a region with high levels of humidity but the weather has been regular for over a month.

Does anyone have any idea why this is happening?
Also, is there any possible way this can be fixed?
If not, should I expect a complete screen replacement?