Today I had applied for a sit and I got a notification that the HO had sent a reply. But I could not read those in the app, the new messages did not show in my inbox. I could read them via the web interface and the browser on my iPhone.
They showed up in my inbox in the app only after I had force-quitted the app and restarted it.
So no big problem, but a bit strange, also because the app gave a notification (I am pretty certain that that worked).
@pietkuip I’ve noticed that too. The email notification arrives but the phone app does not show a new message. What I do now is swipe down- on the inbox -from top to bottom and this seems to refresh the page and the message arrives.
I also have to force close the app to refresh the Inbox, not a great app really.
I also had this yesterday evening . I was notified of a message - but it didn’t appear in my inbox - as I was checking my inbox in my app I was notified of another message - that also was not visible in my inbox.
But a little later they both appeared in my inbox
I’m finding the app particularly useless for messaging - I have to force it to quit and then reopen to even see new messages. I can see new messages on the website, but not on the app, then when I’ve forced refresh of the app, it says the message was sent 3 hours ago! The timing is completely off. When I send a message it tells me it was sent an hour ago despite having only just been sent!
I just tried to send a reply message in the app and it disappeared. Went to main site to send it and received a pop up that messaging is better in the app 
Thank you @pietkuip for reporting this, we have passed it back to the team and will update you when we hear back 
Hello @pietkuip just a quick update for you. The team are currently trying to recreate this issue.
If it is an ongoing issue for any members please can you also reach out to the Membership Services team where they can collect more information such as app version, device and exactly what happened, for example, did you try and refresh the inbox page on the app? The more specific information about the steps you took can help to recreate what is happening.
Outside of that if there are any more updates I will let you know here. Thank you!