The script runs twice in a day. This problem occurred in two specific days (all runs were unsuccessful in these days). Day after and the script worked well again. Yes, connection was established, and the Read Timeout occurred in all iterations of the loop (on the same place). The script was not killed, I use Try::Tiny for that (and send reports via e-mail.) The target file (plain HTML source) is small.
I know that there were similar problems. I didn't expect this to be tho cause, because the read timeout happens exceptionally.