> so I put it between the port and the magnetics

For GP: this is something you would learn from a PHY manufacturer's EVK schematics and layouts. TI (especially), NXP, Microchip show correct magnetics/ESD part numbers and placement - the trickier thing here is finding an EVK that doesn't just use an integrated MagJack.

See https://www.ti.com/lit/df/snlr034/snlr034.pdf