ULTRA++ installation guide

I was having trouble using the device on a raspberry pi 3. I was still running raspbian stretch and it seemed that was a problem. So I updated to buster using

sudo apt-get update
sudo apt-get upgrade
sudo sed -i 's/stretch/buster/g' /etc/apt/sources-list
sudo sed -i 's/stretch/buster/g' /etc/apt/sources-list.d/raspi-list
sudo apt-get remove apt-listchanges
sudo apt-get update
sudo apt-get full-upgrade -y

After the update was finished, I also ran rpi-update to update the firmware. Unfortunately, I still was not able to use the device. To resolve the issue, I installed a fresh raspbian image to another sd card and installed the device on this system. There it worked flawlessly, so I tried to figure out the differences between the two systems.
Turns out, that a specific firmware version seems to work with the device. The firmware version is 5.10.17
To use this specific version in your raspbian OS, use the following command to install it:

sudo rpi-update 78c1429cc1d5a200d824d2629c3ceba4ba4617fe

It works for me, let me know if it works for you.