This has been an issue plagueing me for months and was hoping today's update would fix it but no.
The "export as" window has been broken in photoshop for me - resetting prefrences does not fix it. In "export as" the preview area remains blank and does not show my document, the format dropdown menu is broken and the list area is like 5 pixels wide so you can't see or select the format. The default of JPG is selected and the default quality level is 6, but the quality slider is broken, I can slide the slider to the right to the max of 7 but the slider will not slide to the left.
Also with this new version of photoshop I am missing all of the document presets, just adobe templates.
I have attached a screen recording of the issues and a text file of my photoshop system report - I have reset preferences and reinstalled photoshop and this does not fix these issues. Also I am not experiencing these issues at all in the photoshop beta app.