Xbee - in MicroPython communication by BLE (bluetooth) error ENOBUFS

Hi, I have a problem with the stability of sending data from Xbee via bluetooth (to android application).
In MicroPython in the main loop I have a simple code sending 40 characters (the program sends 5600 characters per second):

    relay.send(relay.BLUETOOTH, ("1234567890123456789012345678901234567890")
except OSError as e:


I perform the tests on the Digi XBee 3 XK3-Z8S-WZM development kit.
One module has been sending data correctly for 4 hours (but crashes after that…), the other one reports an error [Errno 7105] ENOBUFS after about 5 minutes.
Why such a difference in the operation of the same modules?
How to proceed in case of such an error?
For now I restart the modules, is there any programmatic way to get out of this error?
Is there any other way for the module to connect to android? I tried searching for devices via ble.gap_scan, but the mac address of the tablet does not appear.

this looks as though you are not setting up the buffers properly. That is what the Error message is referring to.