mbedtls_handshake: ssl ret -6900 state 8

[formus14]

I'm not sure if this could be indicating an error or bug case .. but it is worth the question.

I am building a simple wss server on the esp that a wss client could connect to it and establish a connection, but sometimes for whatever reason, the connection fails at the handshake as shown below!

[2019/03/05 14:37:22:8823] NOTICE: SYSTEM_EVENT_STA_GOT_IP
[2019/03/05 14:37:22:8848] NOTICE: gapss from LWS_GAPSS_SCAN to LWS_GAPSS_STAT_HAPPY
[2019/03/05 14:37:22:8920] NOTICE:  --- Got IP 192.168.8.107
[2019/03/05 13:37:25:8639] NOTICE: _realloc: size 552: new server wsi (free heap 4184744)

[2019/03/05 13:37:25:8691] NOTICE: lws_gate_accepts: on = 0
[2019/03/05 13:37:25:8706] NOTICE: ssl_pm_handshake
[2019/03/05 13:37:25:8761] NOTICE: mbedtls_handshake: ssl ret -0 state 1
[2019/03/05 13:37:25:8848] NOTICE: mbedtls_handshake: ssl ret -0 state 2
[2019/03/05 13:37:25:8937] NOTICE: mbedtls_handshake: ssl ret -0 state 3
[2019/03/05 13:37:25:9003] NOTICE: mbedtls_handshake: ssl ret -0 state 4
[2019/03/05 13:37:27:0379] NOTICE: mbedtls_handshake: ssl ret -0 state 5
[2019/03/05 13:37:27:0387] NOTICE: mbedtls_handshake: ssl ret -0 state 6
[2019/03/05 13:37:27:0443] NOTICE: mbedtls_handshake: ssl ret -0 state 7
[2019/03/05 13:37:27:0497] NOTICE: mbedtls_handshake: ssl ret -0 state 8
[2019/03/05 13:37:27:0578] NOTICE: mbedtls_handshake: ssl ret -6900 state 8
[2019/03/05 13:37:27:0649] NOTICE: _realloc: size 996: ah struct (free heap 4166508)
[2019/03/05 13:37:27:0751] NOTICE: _realloc: size 1024: ah data (free heap 4165376)
[2019/03/05 13:37:38:0069] NOTICE: lws_gate_accepts: on = 1
E (16947) lwscallback:  # WSI DESTROY

I noticed that the return error code is not 0 by state 8 , could that be pointing somehow on the issue ?

Thanks