I have an issue trying to setup a ZTE K5008-Z modem from Vodafone on a RB951-G 2HND router.
The modem detects the LTE interface and I am able to get DHCP address from it. Also I can access the internet
using this connection after setting a default route.

My problem is that I have a static IP from Vodafone that I want to use to be able to access the router remotely.
I configured the ZTE modem with the right APN, user, pass etc(in it's own web interface) and I am getting my
static ip on the modem's WAN interface.

But I have a DHCP assigned ip on my router and I cannot access it from the internet. Shouldn't there be a way
to do a translation on the modem? I don't really understand how this works. Should it be done automatically?
Because otherwise I cannot see how I can access my router using the public ip.

Please help with some info on this issue if you have tried to do this.

What kind of IP address do you get on your LTE interface? Public or private?
Is the connection in Vodafone based on PPPoE?

This issue can be pretty complicated. If you get your proper public address on the modem, you could access your router through port forwarding, if it's configurable on the modem.

I get a private address on the LTE interface(192.168.9.0/24 class)
I can't tell you if it is pppoe. The interface allows you to declare apn, user, pass.
There is no forwarding option in the modem interface. Or at least not directly accesible.
This is what surprises me because what is the point of having a static ip if you can't access it...
Or maybe I'm missing something.

Also, with other modems I get an USB port on the router. With the LTE modem I only get the LTE interface.
(something related to direct-ip from what i read).
It would be useful if I could create the ppp connection from the router directly but I can't do that
even if i disable direct-ip option.

Well, I'm starting to believe it can't be done using this modem. Or at least not without accessing its nat features(if there are any).
I'm gonna ask for a different modem from Vodafone when I get the chance and request that it is able to do NAT...can't think of anything else.

Is there some USB LTE modem which supports getting public IP on Mikrotik's LTE interface and in 4G mode (transfer rates)? I'm desperately trying to find some solution for replacing DSL connection with LTE, but so far I have not been able to find USB LTE modem which would not make additional NAT.

So far I couldn't find an USB modem to do that.. you can do it with 3g modems though.
I have read you can setup an ppp connection if you enable Ignore DirectIP Modem option but it didn't work for me.
I think the best way to do it is to use a 4g router with it's own mobile interface and put your sim in it and then
connect it to a mikrotik to be able to do what you need. Of course this means you need to do NAT..

we have seen that Sierra MC7710 and Huawei ME909u-521 can get a public IP address.

we have seen that Sierra MC7710 and Huawei ME909u-521 can get a public IP address.

Yes I've read also that those are good choices, but those are MiniPCI-e which means modem is more expensive and not so easy to find at least in my region. Apparently it's difficult to implement "bridged" type of solution with the USB LTE modems. Mikrotik routers are so nice products that I'd really like seeing also this capability in the future, apparently it's not impossible since there are router vendors who have support for large variety of USB LTE modems.

The modem detects the LTE interface and I am able to get DHCP address from it. Also I can access the internet
using this connection after setting a default route.

What is your exact configuration? I am only getting a flashing light while plugged into the Routerboard.

Regarding public IP, I suspect that this is a NAT device, so the public interface is obscured internally.