A couple of things from troubleshoot file, though not sure if related:
The ARP entry of 192.168.1.127 is, for some reason, flagged as incomplete.
Could you login to the router via SSH and try adding it manually with the following command:
- ip neighbor replace 192.168.1.127 lladdr <MAC_address> dev br-lan
Replace <MAC_address> with the MAC of you Linux computer interface's address.
There is also a notification of:
- Port speed for port 4 changed to 10 baseT
Which is rather weird, as router's ports are named LAN1, LAN2, LAN3 and WAN.
Also negotiation of 10baseT mode is unusual. What duplex modes does your industrial device support, could there be a mismatch?
As for packet capture, it only indicates that there are several APR requests from the router to figure out 192.168.1.127 MAC, but no reply is detected.