Can't connect Gateway Mikrotik to The Things Stack running on Localhost

I have just set it up like this, all my local network can access, and gateway appears as disconnected on the things Stack. I have a question that may be the issue. (I have config gateway mikrotik to access server address from IP)

Is possible to have same devices (gateways and end nodes) with obviously same EUI, in different the things stack?
I mean I have gateway in the things stack public server and now in the things stack, private server in localhost too.

Your private stack and TTS CE will not be in direct communication for many many good reasons, not least security. So it is OK to have the same configs on both. However if you have a gateway that is on TTN as well as this Mikrotik, you could end up with a lottery as to which one a device joins.

As for the gateway, as long as its configuration points to the IP address of your private stack and it can ping that IP address, it should be good to go. The update on the connected status can be slow & mislead you - the acid test is to use a device to see what happens on it, the gateway log and the web console.

So now I have one more question for next image:
Screenshot_20220710-124929

These are IP addresses from gateway, the one that it gets from dhcp via ethernet from local network router, 192.168.18.0 where is set my virtual machine via bridge mode to host (192.168.18.2) and network that creates the own gateway (192.168.88.0).

I’m not able to ping dhcp IP from gateway(192.168.18.233), neither ping from gateway to virtual machine’s IP(192.168.18.2 = server address).
Is it possible that i must set virtual machine’s IP, it’s means being connected to wi-fi from gateway (192.168.88.0), to could have that connection between them? And making possible that state of connected y tts?

Pd: I cannot make ping to 192.168.18.233 from my host neither

Are you using a bridge network as explained on VirtualBox Network Settings: All You Need to Know ?
Usually a VM will have just one network adapter, a wired one. Having a wireless adapter in a VM is very unusual.
When using the bridge network your VM should get an IP address in the same range as your PC and you should be able to ping your router and the MikroTik gateway from both.

Yes, I’m able to ping router, my pc and every device in 192.168.18.0 both sides but not gateway(192.168.18.233). No one from my network can ping gateway.
The way I config it, connecting it’s wi-fi, make me think that I must be connected to it for receiving an IP in his network (192.168.88.0).
That’s what i’m gonna try meanwhile how it’s set up now should works.

MikroTik gateways are configured to consider the wired network as WAN so it won’t respond to ping or other connections. You can change this if you want but it’s not required.
From the gateway can you ping the VM?

No I’m only able to ping router (192.168.18.1), because it’s connected via ethernet. I cannot ping VM, pc, or any other device in 192.168.18.0 network

I would start by reconfiguring the MikroTik to have it use the wired port as LAN port.