I am using stunnel to mount an azure nfs file share. 

The stunnel process log the following message

Dec 18 17:55:20 vmubuntu18 stunnel: LOG3[23840]: SSL_connect: Peer suddenly disconnected

The stunnel configure file is

verifyChain = no

debug = debug

output = /etc/stunnel/microsoft/aznfs/nfsv4_fileShare/logs/stunnel_52.239.241.136.log

pid = /etc/stunnel/microsoft/aznfs/nfsv4_fileShare/logs/stunnel_52.239.241.136.pid

TIMEOUTidle = 61

[52.239.241.136]

client = yes

accept = 127.0.0.1:20049

A trace with tcpdump display the following logs

We observe a reset connection between azure server  and my machine.

Best regards

Souheila