NullReferenceException in TMPro.MaterialReference when creating a UI Button - TextMeshPro

Repro steps:

• start a new project
• create a new UI  Button - TextMeshPro in an empty scene
• the TextMeshPro pop-up will appear, and you'll need to install the TMP essentials
• try to select the Text(TMP) child element of the Button in the scene view and move it arround

Expected result:

• the text on the button says "Button"
• no errors appear when moving the text object

Actual result:

• the text is blank
• lots of console errors appear when you try to move the button

Reproducible with: 2023.1.0a10 (TMP 3.0.6)
Not reproducible with: 2019.4.40f1, 2020.3.38f1, 2021.3.10f1, 2022.1.16f1, 2022.2.0b8, 2023.1.0a9 (TMP 3.0.6)

NOTE: this error appears to happen for UI Button text element only. So one workaround could be to create a simple UI TextMeshPro Text game object and add it to a UI button instead.