Okay…needed to add protocol: 8, but still very unreliable this remote (empty line marks remote press):
[10:43:05][D][binary_sensor:036]: 'Funk Fernbedienung': Sending state ON
[10:43:05][D][binary_sensor:036]: 'Funk Fernbedienung': Sending state OFF
[10:43:06][D][binary_sensor:036]: 'Funk Fernbedienung': Sending state ON
[10:43:06][D][binary_sensor:036]: 'Funk Fernbedienung': Sending state OFF
[10:43:06][D][remote.rc_switch:256]: Received RCSwitch Raw: protocol=8 data='10010101'
[10:43:12][D][remote.rc_switch:256]: Received RCSwitch Raw: protocol=8 data='100101010101010110'
[10:43:12][D][binary_sensor:036]: 'Funk Fernbedienung': Sending state ON
[10:43:12][D][binary_sensor:036]: 'Funk Fernbedienung': Sending state OFF
[10:43:15][D][binary_sensor:036]: 'Funk Fernbedienung': Sending state ON
[10:43:15][D][binary_sensor:036]: 'Funk Fernbedienung': Sending state OFF
[10:43:15][D][remote.rc_switch:256]: Received RCSwitch Raw: protocol=8 data='10010101'
[10:43:16][D][binary_sensor:036]: 'Funk Fernbedienung': Sending state ON
[10:43:16][D][binary_sensor:036]: 'Funk Fernbedienung': Sending state OFF
[10:43:20][D][binary_sensor:036]: 'Funk Fernbedienung': Sending state ON
[10:43:20][D][binary_sensor:036]: 'Funk Fernbedienung': Sending state OFF
[10:43:20][D][remote.rc_switch:256]: Received RCSwitch Raw: protocol=8 data='100101010'
[10:43:21][D][remote.rc_switch:256]: Received RCSwitch Raw: protocol=8 data='10010101010101011001010101101'
[10:43:25][D][binary_sensor:036]: 'Funk Fernbedienung': Sending state ON
[10:43:25][D][binary_sensor:036]: 'Funk Fernbedienung': Sending state OFF
[10:43:25][D][remote.rc_switch:256]: Received RCSwitch Raw: protocol=8 data='1010101010101100101010110101001010110100110010110100101010101'
[10:43:25][D][remote.rc_switch:256]: Received RCSwitch Raw: protocol=8 data='10010101010'
[10:43:28][D][remote.rc_switch:256]: Received RCSwitch Raw: protocol=8 data='100101010101010110010101011010100101011010011001011010'
[10:43:29][D][remote.rc_switch:256]: Received RCSwitch Raw: protocol=8 data='10010101010101011001010101101010010101101001100101101001010'
[10:43:33][D][remote.rc_switch:256]: Received RCSwitch Raw: protocol=8 data='1001010101010101'
[10:43:33][D][remote.rc_switch:256]: Received RCSwitch Raw: protocol=8 data='1001010101010101100101'
[10:43:33][D][remote.rc_switch:256]: Received RCSwitch Raw: protocol=8 data='101011010'
Should I dump the remote or use another 433MHz receiver as this one?