Look at this:
there are positioning glitches when:
- using more than one TextBlock
- TextBlocks are not wrapped in any Container
- TextBlocks are linked with meshes
- The Camera and/or the meshes are moving (at slow speed)
there are also glitches enabling resizeToFit (in this case also without moving the camera and with only one object…)
the issue was introduced with this PR: Fixes and performance improvement for linked GUI by carolhmj · Pull Request #13430 · BabylonJS/Babylon.js · GitHub
i found that removing this lines also fixes the issue