Meshtastic has a reliability problem. We often cannot get beyond one hop - and our network isn't too loose nor too dense (60 stations).
Cross test with Meshcore doesn't show any issues. Chats over 5 hops have almost a 100% success rate.
Long time I avoided MC because of its closed source client - but a Opensource Flutter app for Apple/iPhone is slowly getting usable and stable. (https://github.com/zjs81/meshcore-open)