Asterisk 'missing tmp ecdh key' error

Hello all,

I have asterisk 13.9.1 + FreePBX 13 + sipML5 with SIP-account where i can make outbound calls with no problem, but when I send an inbound call to this sip - when i ‘pick up a phone’ in sipML5 - it just disconnects me (the call is hanged up). I can see the following error in the astersk log:

ERROR[23250][C-0000909b]: res_rtp_asterisk.c:2172 __rtp_recvfrom: DTLS failure occurred on RTP instance ‘0x7f152bca2508’ due to reason ‘missing tmp ecdh key’, terminating
WARNING[23250][C-0000909b]: res_rtp_asterisk.c:4048 ast_rtcp_read: RTCP Read error: Unspecified. Hanging up.

OS CentOS 7
OpenSSL 1.0.1e-fips

Сould you please help me or at least point me where should I look at to fix it? I tried A LOT of thing already, but nothing helped.
I would really appreciate any help.