Got optic to SFP bridge from my ISP (only because I insisted on using my own router) , that was fed into SFP to RJ45 adapter that I have bought (via Amazon - apparantly the ISP’s have lobbied to not import it here) and then connected my router.
That went somehow ok untill I switched ISPs , now the optic cable is fed into an ISP provided decryption module , paired specifically to the mac address of my router.

It’s like the ISPs went onboard with upgrading to optic because they could excert more control over their customers.