MBED_37 is failing with STM32F1 and STM32F4

[adustm]

The automatic test serial_auto_nc_rx (MBED_37) is failing for STM32 F1 and STM32F4 families (at least)

HOST: Copy image onto target...
        1 file(s) copied.
HOST: Initialize serial port...
Looking for NUCLEO_F103RB with MBEDLS
...port ready!
HOST: Reset target...
HOST: Property 'timeout' = '20'
HOST: Property 'host_test_name' = 'serial_nc_rx_auto'
HOST: Property 'description' = 'Serial NC RX'
HOST: Property 'test_id' = 'MBED_37'
HOST: Start test...
HOST: Unexpected output. Expected 'RX OK - Expected' but received ''

{{failure}}
{{end}}
Test::Output::Finish
TargetTest::NUCLEO_F103RB[0B1D]::IAR::MBED_37::Serial NC RX [FAIL] in 5.90 of 20
 sec
Test summary:
+--------+---------------------+-----------+---------+------------------+-------
-------------+---------------+-------+
| Result | Target              | Toolchain | Test ID | Test Description | Elapse
d Time (sec) | Timeout (sec) | Loops |
+--------+---------------------+-----------+---------+------------------+-------
-------------+---------------+-------+
| FAIL   | NUCLEO_F103RB[0B1D] | IAR       | MBED_37 | Serial NC RX     |
 5.9         |       20      |  0/1  |
+--------+---------------------+-----------+---------+------------------+-------
-------------+---------------+-------+
Result: 1 FAIL