iodeOS freezes seconds after booting

I am using iodeOS on FP4 more than a year now, and I had several OTAs w/o problems.

But since yesterday, the GUI freezes ~30 seconds after reboot, and after another minute, the system GUI restarts (kernel is still running, since I am still connected via adb).

adb logcat tells me

11-08 18:53:38.323  1772  2366 W InputReader: Received unexpected event (0x35, 0x2fa) for slot 1 with tracking id 11
11-08 18:53:38.323  1772  2366 W InputReader: Received unexpected event (0x36, 0x6c2) for slot 1 with tracking id 11
[...]
11-08 18:53:38.398  1772  2366 W InputReader: Received unexpected event (0x35, 0x2cf) for slot 2 with tracking id -1
11-08 18:53:38.398  1772  2366 W InputReader: Received unexpected event (0x36, 0x683) for slot 2 with tracking id -1
11-08 18:53:38.522  1772  2366 W InputReader: Received unexpected event (0x35, 0x2c1) for slot 1 with tracking id 15
11-08 18:53:38.523  1772  2366 W InputReader: Received unexpected event (0x36, 0x66d) for slot 1 with tracking id 15
11-08 18:53:38.947  9134  9407 E ANRWatchDog: Main Thread not responding
11-08 18:53:38.948  9134  9407 E ANRWatchDog: timeout 3 seconds 
11-08 18:53:38.948  9134  9407 E ANRWatchDog: thread.id 2

I am currently on iodeOS 4.6. The device is rooted, and it does not make any difference if a SIM card and an SD card is inserted or not.

Any help would be appreciated.
Thx, Jack