If you see this PayPal error regarding a remote IP address the solution is very simple.
Disable "Check IPN provider IP" in the PayPal payment method - then the IP address (for the IPN message from PayPal) will not be checked and the invalid IP error will NOT occur.
This also saves having to search for and enter a continually changing list of PayPal server IP addresses.
Many VM/PayPal users have used this setting for a long time with no security issues.
(https://i.ibb.co/rfsvjZb/pp.png)