RTL8201CP PHY interface not working

[alegioit]

Hi all,
this is my first topic. Please do not be mad if I use wrong terms or at my poor English grammar (I'm Italian).

This is my first tinkering with PHY interfaces and as usual, at the first try (for me), nothing works

My goal is to have a microcontroller (stm32f429vgt6) that receives TCP or UDP packets and then do something on its gpio or its other communication buses. To do that I wanted to link the microcontroller with a PHY transceiver (RTL8201CP) using the MII interface.

Long story short I've created the PCB hereby attached, but when I connect the ethernet cable from my switch nothing happens (no link led is lit on the switch or on my circuit): I've already checked with my oscope if something is passing through the link and I see that there are bursts on the RX line of the circuit (so the switch is actively trying to communicate).
I've already checked all the connections and everything seems fine (but if you have a clue that there is a fault connection I'll double-check it!). The RTL8201 is working: when the NRST line is low the chip resets (LEDs turn on briefly) and if I test the 25MHz crystal it resonates correctly.
I think that the problem is located in the connections between the RTL8201 and the ethernet connector (see the attached schematics): I've tried to find a suggested schematic on the Realtek website, but I didn't find any! (if someone has it and he will send it to me I'll appreciate a lot!). So I used the schematic that I've found on the internet, but they differ a lot!
In particular, some of them connect the centre tap of the magnetics that runs to the IC to a decoupled VDD (as I've done), others connect them to GND using a 100nF capacitor and others connect the magnetics directly to the RTL8201 (who is right? I think it depends on the PHY interface ICs, but I can't find anything about it on the RTL8201CP datasheet...). The same happens for the other side of the magnetics (from the magnetics to the rj45 connector): some of them includes the 75ohm resistor others don't...
I am pretty sure that the problem is there because when I was trying to inspect the circuit with my oscope (i had previously removed the 50ohm resistor to see if something was changing) and I connected my oscope probes to the TPTX terminals of the magnetics the collision led started to blink and after trying a couples of times (reset, touch the terminals, reset, touch, etc...) I was able to establish a link (the link led on my circuit was on and so the one on the switch).
I think that all my problem depends on the poor designed PCB, but this is my first try on designing something so em sensitive...

Could you help me in finding the cause (If you need that I do other checking/measurements please ask and I'll do them asap), correct my errors, give me an advice (if you have some documentation about the problem I'll be more than glad to read it!) and maybe help me in correcting my PCB and schematics?

Thanks a lot!

PS: I've zipped all the schematics together to upload and download them easily!