W5500 Not working with 1 switch

Hello!

I have a custom PCB designed using the reference external transformer schematic. I’ve been using the Arduino Ethernet library with the Atmega328p and have had no issues interfacing via TCP or UDP.

I have an end user who wants temperature transmitted via UDP directly to a known remote IP and port.
The end user is having problems receiving UDP data from my board on his switch. He has also only been able to ping the board successfully 3 times out of many attempts .

However, I am able to receive the data straight to my PC, straight to my laptop, and through a router as a gateway for the PC. The end user is also able to receive data just fine on their PC.

After reading through the forums it looks like it may be worth a shot to remove the damping resistors or the ferrite bead between grounds.

Any insight as to what the problem could be would be really appreciated.