[edit]
I got it working:
I added coherent_pool=2M to the bootargs in the uEnv-matrix-v2.txt
[/edit]
I upgraded my Matrix with the latest version and that seems to have solved my issues with SSH. However, my DVB-S cards were detected but didn't show up in the /dev/dvb tree:
[ 7.172751] technisat-usb2: set alternate setting
[ 7.179894] technisat-usb2: firmware version: 17.63
[ 7.179923] dvb-usb: found a 'Technisat SkyStar USB HD (DVB-S/S2)' in warm state.
[ 7.181165] dvb-usb: will pass the complete MPEG2 transport stream to the software demuxer.
[ 7.182796] ERROR: 256 KiB atomic DMA coherent pool is too small!
[ 7.182796] Please increase it with coherent_pool= kernel parameter!
[ 7.183316] dvb-usb: Technisat SkyStar USB HD (DVB-S/S2) error while loading driver (-12)
[ 7.183487] usbcore: registered new interface driver dvb_usb_technisat_usb2
[ 285.942191] usb 1-1.2: new high-speed USB device number 6 using ci_hdrc
[ 286.560311] usb 1-1.2: New USB device found, idVendor=0b48, idProduct=300a
[ 286.560342] usb 1-1.2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[ 286.560364] usb 1-1.2: Product: TT-USB2.0
[ 286.560381] usb 1-1.2: Manufacturer: TechnoTrend
[ 286.560399] usb 1-1.2: SerialNumber: LHJCIÃ
[ 286.599241] dvb-usb: found a 'Technotrend TT Connect S2-3650-CI' in warm state.
[ 286.599289] pctv452e: pctv452e_power_ctrl: 1
[ 286.599289]
[ 286.601603] dvb-usb: will pass the complete MPEG2 transport stream to the software demuxer.
[ 286.602888] dvb-usb: Technotrend TT Connect S2-3650-CI error while loading driver (-12)
[ 286.603101] usbcore: registered new interface driver pctv452e