It’s also possible that it’s the ISP’s fault. See other Bezeq experiences here, maybe something helps?
https://community.roonlabs.com/search?context=topic&context_id=251642&q=bezeq&skip_context=true
In particular:
ARC now supports IPv6 with the regular production version. However, it doesn’t with all of them. I note that your ARC error message does NOT list a v6 address, so possibly Bezeq is not exclusively v6