I managed to revive my phone with SIM detection / IMEI. First: Backup everything, data manually, apps with the android backup tool.
I installed last SONY Android 9 Stock ROM with newflasher. Then, the SIM / IMEI worked again.
Then I flashed first official TWRP 3.7, formated data and wiped dalvic cache/cache/system.
Then I flashed the unofficial TWRP 3.6.2 ByYoshino, formated data and wiped again (for security) and installed IodeOS5 with adb sideload.
IodeOS worked then with SIM / IMEI. I had to recover of course my apps and data manually from the bakcups.
I hope it stays now fixed.