If you have Skynet, I would consider complete blocking of all potential IPs related to Roblox via ASN banning. See steps below:
1. Login to your router via SSH and issue the following command:
then make note of the IP address that you get.
2. On your browser (Internet Explorer, etc), go to:
www.ipinfo.io
and once on that site enter the IP that you got from step 1 above and hit Enter
3. Make note of the ASN info (it will be displayed right below the IP you typed, amongst a bunch of info and it will look like “ASNxxxxx”).
4. Go to Skynet (from your AMTM menu) and choose step 2 (“Ban”).
5. Select option 4 (to ban by ASN and enter your entire ASN from above - include all letters and numbers as shown on step 4).
6. Hit Enter and you are done.
7. To test, close your browser/clear your cache. Open it up again and then type:
www.roblox.com
and if that address does not resolve that means you are good to go.
Hope this helps.