disruptions in network traffic might explain both of these.  You would have to look at a packet trace to better understand what is going on completely.  

On Sunday, June 26, 2016, Agustí Ubalde <aubalde@presenceco.com> wrote:
Hi Anthony,

This could cause that the connection works intermittently? Any idea to solve the problem?

2016-06-23 19:16 GMT+02:00 Anthony Minessale <anthony.minessale@gmail.com>:
It happens when a candidate has not gotten any stun from the expected places but it gets some from another place that is not the right address but does have the right credentials.
It will lock on to the remote destination for that candidate instead.  This is usually encountered when the other side is asymmetric nat. 

On Thu, Jun 23, 2016 at 11:20 AM, Agustí Ubalde <aubalde@presenceco.com> wrote:
HI all,

In the log file I observed the trace Changing Auto stun / rtp / DTLS  It only happens on connections from a particular IP. Anyone know explain to that is?