How to use LoRa telemetry radio, with fixed address

I’m using an EBYTE serial telemetry radio. It supports fixed address communication, where the first three bytes are the destination address, which I’m using for a multiple drone system. I can configure the vehicle and ground station addresses as needed.

When there are pauses (>200ms) between messages, the address bytes (preamble) are correctly interpreted by the module. However, with more frequent messages, or messages that are large, the transmission cuts off and will not transmit until I provide the address bytes again. How can I know when this cutoff is about to happen?