Your iPad Pro 10.5 screen is showing classic signs of de-lamination - a physical fault - resulting in an effect colloquially know as “backlight bleed”. You may also have partial failure of some edge backlighting.
The only solution to this problem is full screen replacement.
If purchased from Apple, or if you have benefit of AppleCare extended warranty/insurance, Apple might offer you an exchange for a reconditioned model (if offered, this may be chargeable). If you are out of your warranty period, or you purchased elsewhere, then a screen repair is likely to be uneconomic - even if you can find an Apple Authorised Service Centre (ASC) to complete the task.
Don’t be tempted to use a non-Authorised repairer - as your iPad will not be fixed properly. The TouchID sensor is affected by this repair - and will not function correctly unless it is correctly re-integrated during the screen repair process - this being an action that only Apple (or an ASC) can successfully perform.
I hope this information is helpful to you.