Problems with HTTP connection

After serverals update on gitlab(last week).

We re facing issue. Gitlab randomly drops http connection(refuse port 80 communication).
Not able to git clone/push/pull for http: “git clone http://…” .

Failed to connect to port 80: Connection refused

But on the other-hand, https or port 443 working without any problem.

Nothing to see in logs, or we re not able to find something.

Is there any way how to debug this problem ?? Thanks.