Sync not working (Unauthorized access – Invalid remote IP address)

Hello,

I’m facing an issue with syncing users between two websites. The synchronization process works flawlessly from Site A to Site B. However, when I attempt to log in from Site B to Site A, I encounter the following error:

“The remote website encountered the following error: Unauthorized access (invalid remote IP address)”

While all incoming and outgoing actions function correctly on Site A, the same actions on Site B result in the mentioned error. I’m seeking advice on a workaround for this issue.