Uart frozen during timeout

Question

Hi. I'm working on a BLE system with Central and Peripheral with nRF5340 with 70msec of CONN_INTERVAL and about 1sec of SUP_TIMEOUT.
The Central unit also has a UART that works with the cpuapp with "Interrupt-driven API" and which sends a message to another device every 100msec (triggered by a dedicated timer) with the uart_fifo_callback api functions.
Everything works quite well, but when the Central unit loses the connection from the Peripheral, the CPUs seem to freeze for the SUP_TIMEOUT time and they also freeze the UART for no reason even if the trigger remains active every 100msec!
I just noticed that if I reduce the SUP_TIMEOUT to 500msec this block is almost completely eliminated.
Thanks in advance for the help.

remtec · Accepted Answer

Well. Apparently just consulting DevZone helps find solutions even if there are no direct replies! :) When the connection was lost, a read/write command request was left pending, blocking the CPU until the timeout occurred. Is there perhaps some other way to avoid this? 
 Thanks anyway for the inspiration! ;)