For me it is very hard to believe, that UE5 is not able to generate a simple Material fade in and out effect without issues. The following screenshot shows a Text made with the 3D Text Plugin of Unreal, and a few cubes and a cylinder. All with the same Material, with Translucent Blend Mode and the opacity set to 1.
The Text got the issues, and the cubes with the cylinder not.
Is there no way to solve this?