Thank you all for your suggestions. Ultimately, the solution was as simple as stupid. For some reason, the Mikrotik did not update properly. While the Quick Set menu showed the system was properly updated, the terminal (/system routerboard print) did not.. After proper update, the link worked proper...

Thanks for the suggestion!
I updated to version 7.14rc1 - same result unfortunately though.

The version description does suggest similar issues with other devices as well indeed..
Maybe I should revert back to e.g. 7.12 or earlier?

Best, J

FYI - I have also tested SFP+ tranceivers from Mikrotik and Ubiquiti, without effect unfortunately

Hi all, I have been having issues with the connection between my Mikrotik Switch and Unifi Switch. I have been able to get a connection working if I fix the connection to 1GB full duplex, but auto-negotiate or 10GB fail... How can I troubleshoot this problem properly? The situation: Mikrotik SwitchC...

Ok, after extensive frustration, and breaking the whole thing at some point, it works again, but only at 1 GbE :s
Since this is possibly a different issue, I will start a new thread.
Thanks @IIKa!

Hi, I am new to MikroTik, so I may be doing something straight up stupid :D I have a MikroTik CRS312-4C+8XG running as a switch on RouterOS 7.13.4. Uplink on SFP+ port 1 to a Unifi switch and gateway. Interestingly / annoyingly: Internet works upstream (in the unifi part of the network) Internet som...