why my xbee paused when sending data with XBEE wi-fi S6B

i make a connection between an arduino teensy 3.6 and my computer with 2 xbee wi-fi S6B (baudrate at 460800), my frequency of sending data is 1 Khz.
at start everything works well , the data is transmited at a good rate , but after about 16 secondes, the stremaing is stopped for approximatly 10 secondes . this sequence of start and stop is repeat over and over.
i don’t understsand why i have this behaviour … if someone have i idea where i can make a mistake in my configuration.

Baud rate, buffers Etc.