Keyboard woes (Framework 13 Intel i7, 11 Gen )

Recently, some time after the BIOS update (3.24) and installation of Zorin OS 17.3 Pro, the following keys stopped working:

x, z, F2/volume down, F1/mute, s, 2, w, Escape

According to the keyboard matrix, this is column 5.

To make sure it’s not a software problem, I tried a number of operating systems with the help of Ventoy. Result: same thing.

The keyboard connector on the motherboard looks fine and I don’t see any cracks or anything like that in the flat connection cable.

Of course I asked Framework support for help, nevertheless: does one of you an idea? Should I replace the flat cable? The complete keyboard?