First ensure that your config file has the appropriate certificates and ApiKeys like:
{
"ListenAddress":":8066",
"ThrottlePerSec":300,
"ThrottleMemoryStoreSize":50000,
"ThrottleVaryByHeader":"X-Forwarded-For",
"EnableMetrics": false,
"ApplePushSettings": [
{
"Type" : "apple_rnbeta",
"ApplePushUseDevelopment": false,
"ApplePushCertPrivate": "./config/aps_rnbeta_production_priv.pem",
"ApplePushCertPassword": "",
"ApplePushTopic": "com.mattermost.rnbeta"
},
{
"Type" : "apple",
"ApplePushUseDevelopment": false,
"ApplePushCertPrivate": "./config/aps_rn_production_priv.pem",
"ApplePushCertPassword": "",
"ApplePushTopic": "com.mattermost.rn"
}
],
"AndroidPushSettings": [
{
"Type" : "android_rn",
"AndroidApiKey": "AIzaSyA1sl9LXXXxXXXxXXXxXXXxX_XXXXXX"
},
{
"Type" : "android",
"AndroidApiKey": "AIzaSyA1sl9LXXXxXXXyXXXxXXXyX_XXXXYY"
}
]
}
That being said just because you are using your own push-proxy server you need to build and compile the apps yourself so that the above certificates and Android ApiKeys match with your registered device tokens.
when building the app yourself don't forget to change the bundleId on iOS and packageId on Android so they also match with your certificates and keys.