This is an old issue that was talked about a few years back. This issue is however still relevant, as it is still a problem. So what can you do to fix this issue? You could make the text object’s TextScaled = true and then RichText = true. Apparently this fixes it, but it also disallows any newer objects like UIStrokes to be displayed at all.
There is also one more downside to it. And that is if you reach a certain size of the part you have the surface on it, it will have problems rendering the text itself.
This bug can’t really be fixed, first of all, text without RichText is limited to size 100, this is due to the font only giving scales up to scale 100, allowing a larger size creates blur. Fonts with RichText can be streched to go much larger (although become blurry). RichText disappearing at a large size, while it is a bug, is only mentioned in the replies of this post and is not super likely to be looked at.