I noticed once in the Asterisk console that the following messages are often displayed:
— Remote UNIX connection
— Remote UNIX connection disconnected
— Remote UNIX connection
— Remote UNIX connection disconnected
— Remote UNIX connection
— Remote UNIX connection disconnected
…
The message notifies that someone is connecting to the Astersik console.
These messages are visible if the console is open in debug mode above the -rvv level (that is, if you run astersik -rvvv for example, the more letters v the more detailed information is displayed in the console).
The reason for these messages in my case was Zabbix, which monitored various statistics as I described in this article – Asterisk monitoring in Zabbix
That is, he executed commands like this and received information in this way:
asterisk -rx "database show" | grep Registry | wc -l
Similarly, there may be other scripts or maybe just someone connects.