We are aware of this quirk since it is related to variable fonts and how macOS influences Sketch.
To help you, can you tell me: when double-clicking directly on the text layer restores the ability to make alterations to the text section of the inspector menu when you see this situation?
I’ve seen cases where this restores the editing abilities of this section.
I have the same issue. Double-clicking the text layer doesn’t help either.
This may or mayn’t be related but the editor also just becomes slow in this scenario. For example, there’s a noticeable delay in selecting the text layer and having the inspector respond.
I’m sorry that my solution is not working here. Please, could you send me a sample document containing an affected text layer so I can perform additional tests?
The issue seems to happen with all textfields and all variable fonts.
I’ve sent you a Sketch file anyway, although it should be very easy to reproduce on your side.