it helps some times The extra space you are seeing which is causing the overflow onto the new line is caused by your due to a conflict between the position styles. The size and padding of the icon is still being set in place even though it's moved.
Making fixed-width grid columns and rows in UWP
By : Barbara Coleman
Date : March 29 2020, 07:55 AM
To fix this issue Your main Grid is fixed at 800 x 450 px. If you remove that restriction, the grid will stretch appropriately