My site, https://cuttle.xyz which I host as a static site on Render was recently added to some kind of spam ban list.
It originally affected McAfee and Norton antivirus software (users first reported this Dec 13, 2023) and then recently (Dec 26, 2023) it affected ISP’s Spectrum and xfinity/comcast. In each of these cases, most people can access the site but anyone with the affected ISPs or antivirus software on their computers or routers cannot access it.
The fix has been to fill out forms or call these companies to ask them to take us off their ban list and eventually it’s resolved. (Of course this is a big headache!)
I cannot verify this but one theory we had is that our site is hosted on a shared Render IP address and nefarious actors are hosting spam/phishing/etc on this and then the IP or our domain was somehow added to a ban list.
For example, one of the IPs that our domain resolves to is Render’s 216.24.57.3 and this site shows several reports of abuse from that IP:
https://www.abuseipdb.com/check/216.24.57.3
Anyhow, I mostly wanted to report this in case any other Render customers are experiencing similar issues. Or if you think my theory is unlikely or have suggestions for how I can understand and fix this issue, that info would also be appreciated 
Thanks!