IAX trunk "No authority found" and "ignoring bind port on reload"

I have been having problems lately with an IAX trunk between two Asterisk servers.

Calling only works one way, I am getting an ignoring bindport on reload and a REJECT, no authority found, CAUSE CODE 50 on the server I can’t call to.

[2017-04-10 19:23:53] NOTICE[22325]: chan_iax2.c:13567 set_config: Ignoring bindport on reload
[2017-04-10 19:23:53] NOTICE[22325]: chan_iax2.c:13628 set_config: Ignoring bindaddr on reload

Tx-Frame Retry[000] – OSeqno: 001 ISeqno: 002 Type: IAX Subclass: REJECT
Timestamp: 00100ms SCall: 00641 DCall: 21301 [IPADDRESS:31071]
CAUSE : No authority found

What could be the problem?
The server I can’t call to is Asterisk 11.25.1, the other one 13.13.1

Anybody who has an idea?

You would need to provide the configuration and exact Dial command you are using.