@Darksavior mine drops to the console if that's where I start it or if from ES, drops me back there.

I'll try mitus suggestion first and see how that goes. It would be nice to be able to use this as I move my computer to the living room currently each time for the wife and I to game.

I finally brought my Pi4 home today so I might just give this a shot as well and see what happens with both retropie and SL later on.

@meynti hi there. I briefly came across this problem but figured it out quite quickly.

This control pad has 4 different methods of how the controller will work.
Nintendo switch
Dinput
Xinput
Mac OS

Same as you. Mine was setup to switch mode. Works with the pie. But not steam link.

Dinput also doesn’t work with steam link.

Xinput did work perfectly.

Haven’t tried Mac OS mode but would suspect it wouldn’t work.

Here’s how to sort it.
Get a keyboard ready or another controller that is setup to work on your pie. . You’ll need it soon.

First of. Go to RetroPie Bluetooth settings. Remove your controller from the list.

Now. Turn off your controller. Hold start for 10 seconds.

Hold X and press start to turn the controller on. The X will turn it on in Xinput mode. Two lights should be flashing below the sticks.

Now add your controller again on the pie.

Once done you can quit the Bluetooth settings. You’ll need to go to the bit to configure inputs. If you have another controller that already works on the pie then the start button will bring up this menu you need. From here reconfigure your 8bitdo controller buttons.

Once you’ve done that the steam link will now see your controller. It will say it’s a Xbox one controller but it will work fine. It did for me.

Hope this helps.