Add me to the list. Delayed notifications across multiple services only when connected to Virgin Mobile 4G.
Even with the phone active, the network activity isn't correct. As an example, earlier I was trying to have a conversation with someone on Google Hangouts. Messages would only come through if I left the chat and rejoined it again. There should be a row of three dots to indicate the other person is typing but these never appear. On re-entering the chat again, immediately a new message appears. I tried on a different connection a few minutes later and not using Virgin 4G, there were the typing dots and messages came through instantly.
This is not related to anything on customer's devices so advising to turn off battery optimisation etc won't help. If the device was at fault it would surely be the same when connected to any network.