I have a TP-Link T1600G-28PS core switch that just has a very basic setup with the default VLAN untagged as a staff network and a tagged VLAN as a guest network.
The switches are connected with multi mode fibre with Mikrotik SFP modules in both switches. I can not get any traffic to pass between the TP-Link switch and the Mikrotik switch BUT I can see the MAC addresses and associated VLANs of many hosts that are connected to the TP-Link switch under the "Hosts" tab on the Mikrotik switch.
I've played with flow control disabled and enabled, manually adding VLAN 1 as a VLAN in the VLANs section as well as various VLAN settings in the per-port settings but never once have I been able to get any traffic to pass. No DHCP. No IP traffic if I statically assign an IP on my management laptop. Nothing.
I spent 2 hours playing with it today. Unfortunately it's a 1 hour drive away. The Mikrotik switches were supplied by the data cabler and have already been charged to the client so I really want to make them work.