Outline-Problem with Text in 3D-space

[useless-hyphen]

I was experimenting with Text-Entitiey in 3D-space ( for player-overhead-panels or entity-labeling).
Setting the parent to scene, position, rotation,... everything works like a normal Entity.

But when I move around and facing the Text-Entity from certain angles, it gets a grey outline. It has something to do with creating a text-background or placing the Text close on an other Entity.

I suspect that the grey pixels from the outline could be bluring pixel from the font that turns to grey because of conflicts by rendering.
Maybe there is something I missed by checking ursina.text.py?
Or does anyone know better about panda3D Textnodes? (TextNodes.py or TextProperties.py have more than 5.000 lines of code and every hint would be helpfull)