Packet capture shows below
POST HTTP/1.1
HOST: 192.168.x.x
Connection: Close
Content-Type: application/x-www-form-urlencoded
Content-Length: 194
PASSKEY=xxxxxxxxxxxxx&stationtype=EasyWeatherV1.5.6&dateutc=2021-01-22+08:23:31&tempinf=75.2&humidityin=39&baromrelin=29.481&baromabsin=28.881&freq=433M&model=WS2900C_V2.01.10
however syslog shows
22/1/21 9:20 AM weewx.service weewx[125650] DEBUG user.interceptor: POST: b'PASSKEY=XXXX&stationtype=EasyWeatherV1.5.6&dateutc=2021-01-22+08:21:31&tempinf=75.2&humidityin=39&baromrelin=29.478&baromabsin=28.878&freq=433M&model=WS2900C_V2.01.10'
22/1/21 9:20 AM weewx.service weewx[125650] DEBUG user.interceptor: raw data: b'PASSKEY=XXXX stationtype=EasyWeatherV1.5.6&dateutc=2021-01-22+08:21:31&tempinf=75.2&humidityin=39&baromrelin=29.478&baromabsin=28.878&freq=433M&model=WS2900C_V2.01.10'
22/1/21 9:20 AM weewx.service weewx[125650] INFO user.interceptor: unrecognized parameter b'PASSKEY=XXXX