I see some issues related with double splash screen thing on Google's issue tracker.

False positive warning on Google Play Console "Double SplashScreen"

Duplicate Splash Screen Issue on Google Play Console Pre-Launch Report

They suggest that many users are experiencing this as well. Pre-Launch Reports show that Google Pixel 7 emulators generally experienced this warning.

It seems like the condition or test triggering this warning is unreliable. Unfortunately, there’s still no response from Google engineers. But I think it is some kind of false positive situation.