So just to clear things, there's two levels of whitelisting or filtering which can apply.
1. At the OLT level, the OLT can be configured to allow only specific whitelisted
ONT devices to register with the OLT. This is to prevent any rogue ONT from registering with the OLT. The OLT here can use multiple parameters to allow the ONT to register, it could be the serial number, LOID or even a username+password.
2.
Mac binding at the PPPoE layer. The authentication is allowed only from whitelisted ethernet mac address. This is like a second layer of authentication in addition to the user+password.
Now in this case, it appears to be the first one. Some ONTs allow you to clone these auth parameters, like change the serial or LOID or even the username and password (this is a separate username and password used to auth with the OLT)
Unfortunately, the ONT UI shown in the screenshots, doesn't appear to support modifying these parameters. Please navigate to the different pages on the management UI and see if you have an option to change serial or LOID or username+password. Note that this is different from the WAN profiles.
The ZTE based ONTs like the ones without telephone port from
Syrotech do support changing these parameters.