Bought a UNAS 2 through a local vendor in Europe but it keeps dropping connection at 2.5 GbE

I read a lot about these issues and probably should have ordered straight from Ubiquiti EU store to get a latest unit. I just set up everything and clearly see in the logs that every 1-2 minutes the UNAS disconnects and connects in a few seconds. It is connected directly to my UCG Fiber and once I dropped the port to 1 GbE it's been running smoothly without any issues.

I can immediately return it to the local vendor and either get a new unit or get my money back and order directly from Ubiquiti EU site. Do you think I should keep trying troubleshooting this one or just get a replacement? If I get a new one should I get it again from the local vendor since that is faster and easier or is there a high chance the new unit will have issues too?