Imunify360 Popup

How long have you had that Public IP (i.e. your AT&T account)?

Ive had ATT service since mid-June 2022

For more details about what's happening, your "dynamic" public IP (assigned to you by AT&T) is on Imunify360's Gray List, for more information on the Gray List (as viewed by potential customers of the Imunify360 WAF service), see https://www.imunify360.com/getting-started-firewall/, a more detailed discussion is here: https://cloudlinux.zendesk.com/hc/en-us/articles/4411987171986-How-graylisting-blacklisting-works

You might want to check your IP on some reputation checkers such as Akamai's Client IP Reputation Lookup

If you've had the address for 8 months, I would have thought any prior "bad-behavior" would have aged off a list like theirs, but I really don't know how they manage their lists.  You may have done something innocuous that Imunify360 views as suspicious.  I see no information offered by them for people who are affected by their decision that you are potentially malicious.  So your options may be to ask the website host to whitelist your IP or to quit using Imunify360 (neither is likely unless they're small site), use a VPN to access that site (which would cloak your public IP), or switch to another ISP to get a different IP (because AT&T does not provide a mechanism to change your public IP).

Jeffer, thanks for the info.   Since my initial post, I rebooted my gateway and router.  I was then able to access the same website without triggering the popup.  Other than a gateway reboot, is a new IP address issued on a regular basis or does it require a gateway or router reboot to result in a new IP address?

Other than a gateway reboot, is a new IP address issued on a regular basis or does it require a gateway or router reboot to result in a new IP address?

None of these things will get you a new IP address.  If you read the articles I linked above, it does say that if an address that is sent the Capcha page successfully answers the Capcha, then that IP is removed from the gray list.  I'm going to assume that has happened for you... at least until Imunify360 decides to put you back on it.