In our network, we mostly use Cisco switching products. IOS. normally we use a Native VLAN to pass miscellaneous untagged packets in the trunk port, we use (VLAN ID 4000). I am not that familiar with SwOS Web interface to make something similar to a Native VLAN.

I am trying to understand this:
https://help.mikrotik.com/docs/pages/vi ... ybridPorts

but it’s confusing to make sense of, at least for me.

"Trunk with native VLAN" in Cisco is "hybrid" in Mikrotik. So configure port to: "vlan receive - any" and set "default vlan id" to "native VLAN ID" of your choice (e.g. 4000). You have to mark such port as member of VLAN with "native VLAN ID" (e.g. 4000). In mikrotik "native VLAN" is not setup any different than the rest of VLANs.