We created production variant for iOS and connected our application to it. Some devices registered to production variant with developer token not production. When these devices are marked as receiving push messages, messages are not delivered to all devices even if they are registered with production token.
When only devices with application from appStore(they register with production token) are receiving messages in Push server, everything works.

It looks like when message sending fails on one badly registered device - developer token in production variant - it stops trying to send message on the rest of devices although they can be ok.