[wyman]

I just updated to 2021.3.1 and my customized soft keys got wiped and reset to the defaults shown on those screenshots, too. It's been a minute since I originally programmed them, so I don't remember if this was how I did it originally, but for modifiers:

Make sure to open the EuControl settings from Pro Tools (it programs the soft keys specific to the application)

Choose "Soft Keys" from the top menu

Choose "S1 Track Color Keys" from "Section" menu

Select the Softkey on the EuControl Graphic you wish to assign a modifier to, then click the "Command" button in the EuControl window

Click "Add New" and select "Eucon" from the menu

Under "Details," scroll down until you see "OS Modifiers." Assign the desired modifier to the soft key. Lather, rinse, repeat.

Hope this helps!