Portenta H7 Custom carrier Board

I made a first pass at making a carrier board for my H7 project, and everything worked (I2C, GPIO, SPI etc) except the ethernet.

I used a different Adam Tech part (MTJ-88TUX1-FSD-VL5-M236Y-HT-TR) which I thought would be compatible, but no connection (times out on Ethernet.begin() function).

I routed the 4 pairs of ethernet wires, the LED connections, as well as the shield and TCT connections.

I had routed all the ethernet connections as differential pairs on a 4 layer board (6 mil trace 5 mil space), but realize now that that may have been inappropriate from an impedance calculation standpoint. All the traces were about 1.7" long, and were matched to length between each pair, as well as each member of the pair (delay and phase tunes added). Could not figure out what is wrong with board (all connections are good on double checking).

I am planning to respin the board using the same connector as on the breakout board ( MTJ-88AX1-FS-TSMT-P-L5-M398AC-WOT-K), just to eliminate as many variables as possible.

Has anyone created a board using this connector? I plan on using jlcpcb again, and for 100 ohms, I am getting 8.68 mil trace width with 8 mil trace space (from the jlcpcb calculator on the 4 layer quote ). I would also keep the copper pour at least 30 mils away.

Any suggestions or comments - hoping to get it right this time?

Just for the record, my 3rd spin of the board works. What was changed was as follows (and not sure what was the actual part that helped)

I used the same Ethernet connector as the breakout board - MTJ-88AX1-FS-TSMT-P-L5-M398AC-WOT-K

I made the differential traces accurate to 1 mil (in terms of phase and length between the pairs). This one was the case before

I used 8 mil trace and 8 mil space for a calculated impedance of 100 Ohms as per JLC web site calculator

I will stick with the above for now, but plan one one more revision to try to get POE on the custom carrier board. I will do that only after the current board has all aspects of the design tested.