Just wanted to answer the question myself:
I had to solder a decoupling-capacitor to the radios and everything worked:
https://www.mysensors.org/build/connect_radio#connecting-a-decoupling-capacitor

The Gateway Log just says:

Seems to be no messages from the nodes coming

Has someone an idea?

Die Logfile of the gateway in FHEM says:
2018.07.05 23:43:13 3: Opening MySensorGateway device 192.168.178.62:5003
2018.07.05 23:43:13 5: MYSENSORS send: Rx: fr=000 ci=000 c=003(C_INTERNAL ) st=002(I_VERSION ) ack=0 ''

2018.07.05 23:43:13 5: SW: 303b303b333b303b323b0a
2018.07.05 23:43:13 3: MySensorGateway device opened
2018.07.05 23:43:13 5: MYSENSORS/RAW: /0;255;3;0;14;Gateway startup complete.

2018.07.05 23:43:13 5: MYSENSORS Read: Rx: fr=000 ci=255 c=003(C_INTERNAL ) st=014(I_GATEWAY_READY ) ack=0 'Gateway startup complete.'

2018.07.05 23:43:13 5: MYSENSORS/RAW: /0;255;0;0;18;2.3.0

2018.07.05 23:43:13 5: MYSENSORS Read: Rx: fr=000 ci=255 c=000(C_PRESENTATION) st=018(S_ARDUINO_REPEATER_NODE) ack=0 '2.3.0'

2018.07.05 23:43:13 5: MYSENSORS/RAW: /0;255;3;0;2;2.3.0

2018.07.05 23:43:13 5: MYSENSORS Read: Rx: fr=000 ci=255 c=003(C_INTERNAL ) st=002(I_VERSION ) ack=0 '2.3.0'

The Serialmonitor of the node says:

I am not yet an expert in mysensors and would be glad if someone could help me.

Ok, sorry - here the translation of my first post:
I have some problems connection my node to the gateway

The situation:

• Mysensors (2.2.0)
• controller ist FHEM (latest version)
• gateway is a esp8266 with nRF24L01 connected
• gateway is successfull connected to my wlan
• gateway is successfull connected to FHEM ()status connected and opened, inclusion-mode is on, autocreate is on)

I uploaded a sketch to an arduino uno, connected the distance sensor (coming directly from mysensors.org).

In the Serial Monitor I see that the arduino seems to have problems connecting to the gateway:
527918 TSF:MSG:SEND,2-2-255-255,s=255,c=3,t=7,pt=0,l=0,sg=0,ft=0,st=OK:
529926 !TSM:FPAR:NO REPLY
529928 TSM:FPAR
531527 TSF:MSG:SEND,2-2-255-255,s=255,c=3,t=7,pt=0,l=0,sg=0,ft=0,st=OK:
533535 !TSM:FPAR:FAIL
533537 TSM:FAIL:CNT=7
533539 TSM:FAIL:DIS
533541 TSF:TDI:TSL

Would be great if you could help me!

Habe Probleme, meinen Node ans Gateway zu connecten.
MySensors 2.2.0
Controller FHEM (neueste Version)
Gateway ist ein ESP8266 mit nRF24L01+
Gateway ist mit meinem WLan verbunden.
Gateway ist mit meinem FHEM verbunden (connected und opened).
inclusion-mode in FHEM habe ich an
autocreate ist an

Jetzt habe ich einen Arduino Uno mit Distance Sensor angeschlossen, sketch upgeloaded (aus den beispielen von mysensors), allerdings sehe ich am SerialMonitor, dass sich der Arduino scheinbar nicht mit dem Gateway verbindet:

527918 TSF:MSG:SEND,2-2-255-255,s=255,c=3,t=7,pt=0,l=0,sg=0,ft=0,st=OK:
529926 !TSM:FPAR:NO REPLY
529928 TSM:FPAR
531527 TSF:MSG:SEND,2-2-255-255,s=255,c=3,t=7,pt=0,l=0,sg=0,ft=0,st=OK:
533535 !TSM:FPAR:FAIL
533537 TSM:FAIL:CNT=7
533539 TSM:FAIL:DIS
533541 TSF:TDI:TSL

Habe schon alles mögliche erfolglos versucht.

Bin für jeden Tipp dankbar!