How to fix Safari IP address swapping issues on iPad and MacBook Air?

Something is wrong with Safari when trying to access a local home network address.

When using Apple's Private Relay I type my home router IP address 192.168.50.1, the login page shows up and tapping on user ID Apple Password is popping up letting me to log in.

When switching off Private Relay and entering the mentioned IP this is swapped in no time to asusrouter.com, I get the login page with a warning in red characters - Not Secure and no password is popping up. This happens on iPad and on Mac, bot with latest software. No such behavior with Brave browser on both devices.

[Re-Titled by Moderator]

Original Title: Safari swaps IP address