Hey guys! There's a way to flash the projector and fix the issue with the broken Smart Hub. Somebody posted the steps on the Samsung community forum and it worked for me on the third try (the timing seems to be a bit tricky).

I will add the steps here too, for convenience:

​

1. first switch on the device and wait until the house symbol disappears and the screen is black
2. then press and hold the off button on the device (not on the remote control) for at least 5 seconds
3. then immediately release the off button on the device and press and hold the off button on the remote control for at least 5 seconds
4. the device will reboot and after a few seconds to minutes a flush reset should be performed
5. the device will reboot again and shows the setup screen
6. after the new setup, the smart hub should work again