[PROBLEM] HiFiBerry Digi Pro on RPi 4 no go

[timbarnes]

It seems that this is a conflict caused by a design change in more recent Raspberry Pi 4s. There's a note to this effect on Hifiberry's website, although they state it only applies to a more recent Digi board.

I found that of the two Pi 4s I own, one works with my Digi+ Pro, and the other (slightly newer one) does not. 

Here's a link to the article on Hifiberry's website.