The websocket cannot connec over SSL

[g0l0_sk]

Hi there,
We are trying to implement OCPP 1.6J through websocket. The problem is, when we are use wifi, the webscoket can't establish a connection to the server via SSL. Otherwise, ethernet and LTE modem works well with the same configuration of the websocket. I tried setup certificate manually but with the same results. If we are tried to connect to another test server(via TSL - ws//...), it works.
Could you advise me on where to look for the error or what to try? Could this be related to some settings in the SDK config?
Thx for help and have a nice day.