Problem:
Variable font not working in Indesign.
Main problems with Monotype Helvetica Neue Variable, but sometimes others also cause problems.
(Note: via my Myfonts I received a new font-file and installed this - same problems - so it is not the font file which is broken…)
I discovered that the program/software/app Indesign itself is causing this problem - not only the variable function does not work any more - as soon as I try to use the variable function the whole document is not working properly: can't save, can’t undo, etc !!!
This makes working with a variable font in Indesign very risky (it looks like it is happening with more variable typefaces).

I use
Mac OS - Sonoma 14.4.1
Adobe Indesign 19.3

Description / Example
- when resizing size 60pt (display Bold) via the 'Font size panel' to a smaller size 24pt, it doesn’t change to ’Text Bold’ (what it should do) - but changes to another font (Minion Pro) !
(see screendumps 1 and 2)
- changing it via the Variable Font slider (any of the 3 sliders) does not work either - and I can’t 'undo’ or ‘save' anymore in the file!! Closing and re-opening the file does not help - I have to restart Insdesign to be able to use the undo and save function.
(see screendumps 3 and 4)

Please let me know if there are any solutions!!