I replaced the wifi router from Asus RT-AC87U to Asus RT-AX86U. Kept old wifi ssid and password. And got problems with the sensor - it does connect to the new router, it does request the ip from dhcp, but no data is transmitted, no ping, no connection to the web interface of the sensor is possible.
The sensor does not bring his AP online, so from his side it looks like it’s connected to the router. Switching down the router forced the sensor to switch its AP and let me to reconfigure it to use the old router.
Switching on the old router brings the sensor online.
All other smart home devices (both different Sonoff’s and self made esp8266 with same boards as in the sensor) successfully connect to the new router.
The sensor is in 3 meters from the router, so the signal is perfect.
What can be the problem? Should I play with router settings or may be I should change from 802.11n to b or g mode (I found some discussions regarding possible problems with n mode in ESP8266)?