I'm using the LR1121 version of the T-Lora Pager and it seems that there is a problem with the Pager transmitting the ACK after receiving a packet.
The device does receive the message, but the sender does not get the ACK. And then the Pager keeps trying (the green dot in the Ultra firmware is on), but never sends that ACK out. While the Pager is doing it, it is not receiving any new messages. A workaround is to try to send out a typed-in message from the Pager, and then it would receive one message again, and would get stuck into that ACK cycle.
Works good with Meshtastic though (if we consider the Base UI "good", anyway).