I can’t easily find the tech specs for the Acid C|24, as the Avid site is returning 502 gateway errors.
I did locate the manual, and it both lacks any reference to Ethernet speed, and does mention the need for using a cross-over cable for some configurations. Which in aggregate usually means it’s not gigabit, and won’t (directly) work here. (Gigabit connections will usually automatically manage the use of direct and cross-over patch cables.)
This Avid box and the Mac will probably work when connected via a switch capable of 10, 100, and 1000 Mbps (gigabit) Ethernet speeds, however. This if the router is somehow getting tangled, or if there are multiple routers or multiple subnets here.
Some more general networking questions:
How many IP network routers are installed here?
Have you restarted the router?
Checked the Avid C|24 firmware?
All of the patch cables here should be Cat 5E, Cat 6, or Cat 6A.
Avid C|24 is originally from 2011 and apparently went unsupported in 2022, as well.