Checked logs of Konrad again to get information about the context
Found the timer thread, which halted on the sending votes. It leads to the state when the node is only sending votes without receiving anything.
Node was in that state for 22 minutes.
Seems like that it is directly related to the problem in network communication. A single node is blocking other nodes to work correctly.
We need to understand the behaviour of threads in different nodes. Currently, I am working on Iroha architecture analysis and find the reason for halt.