Tinder messages disappeared? Get them back without compromising your privacy
Tinder Matches and Messages Disappear, Not Showing Up, Loading in App After Crash
How to Fix Tinder Messages Not Showing
Make sure to turn off Wi-Fi once you have done this.
Make sure you try and do these once you have exchanged a few messages back and forth and not just off the bat.
Even if this might not have a direct issue with your messages not showing up, it is still good practice to do this.
The development of brand new app does not appear to be accomplished.