iPhone speaker sounds scratchy when in landscape

Hi

it’s been only 4 months of buying my iPhone 13 and the external speaker sounds scratchy when in landscape mode, but sounds fine when in portrait mode.

There’s nothing obstructing the speakers, it hasn’t been exposed to water damage, it is not limited to any specific app and the problem is across the device regardless of the app or program

This problem does not exist while wearing earphones and I believe its clearly and external hardware problem

Please help