Loose messages

Trying to introduce Digi mesh in the data collection system.
±-----+ ±-----+
| XBee master| <---------> | XBee slave|
±-----+ | ±-----+
| XBee |

DigiMesh is set in default broadcast mode.
Discovers oddity: In the system with one master. It sends requests and receives responses. The answer comes immediately after receiving the request. If I send a short query (10-12 bytes), then have the response. If I just send a second request, then have no response, while though the monitor see the request and response. If I wait a second query about 0,2 s, then the response comes. If I send a long query (80 -100 bytes), then have no response (monitor see the request and response). If answer come with timeout, it’s OK.
Seems Xbee after transmit can loose incoming message!

Found that I wait too small.
After long request, XBee something waits and response will come after 0,2…0,3 s. It’s strange and means that we can’t predict response time.