Lost connection from software placed inside docker container

I have strange issue with docker container. My current container have to working with cryptocoin daemon.
It working, but about 99,99% connection to external world from container is unsuccessful. I have two message - connection refused or no route to host. This message repeated thousands times with various different external IP.

As a result of this issue during one day my daemon handle less than 100 blocks instead expected 100,000 blocks (this is usually blocks count without placing the same software inside docker).

I try to install PING inside image to check IP addr with message “no route to host”, unfortunately installation failed. I try to start apt install more than 10 times and always connection was lost after 10-20-30 %.

Memory and other resources is enough inside container:

What possible reason of this issue? What additional test I need to do for detection this issue?

Could you solve it? Did that connection issue happen only inside containers or also on the host machine?