I am using mainly my laptop, but I also tried a relative's desktop computer and had the same problem. I do not know if my ISP is using anything, but I got this with two different ISPs that I switched between.
When I use the exact same laptop through the university (now) and when I used it from an ISP in Germany, I had no problems. It looks as if the board blocks entire ISPs in Israel. Can it be related to dynamic IPs?