Device without Gateway not reachable over VPN?

Hi everyone, I setup VMWare ESXi 6.7 with a Virtual Mikrotik (CHR).

Here is my setup:
Only one internet connexion but with 6 static IP’s.
it’s connected directly in my Server.

ESXi 6.7 Hypervisor running multiple Virtual machines, one of them is Mikrotik CHR.

On the Mikrotik CHR, I setup 2 ports: WAN and LAN

ESXi Server (Management Interface) is using one of static IP from the provider, and Mikrotik WAN is using another static IP.

BUT, I setup another “Internal” ESXi management network with an IP that’s in range of Mikrotik’s LAN side.

So if you know ESXi, there are no possibility to setup 2 Management interfaces with 2 Gateway, so the main Management interface of ESXi uses Internet Provider’s gateway.
So I can’t setup any gateway on second management interface on LAN side! (normal: I don’t think any device can run with 2 separate gateway!??)

I can reach and configure ESXi from anywhere by it’s public IP.
I can also reach and configure ESXi from LAN side by it’s private IP (but ONLY with Virtual Machines that uses LAN side of Mikrotik CHR).

What I tray to do is to be able to reach Private IP of ESXi over VPN connection!

I can reach any LAN device from remote VPN connection except Second ESXi management interface.

Note that I use Mikrotik PPTP VPN.
PPTP Server is the Mikrotik CHR, and my PPTP Client is another Physical Mikrotik.

Everything works perfectly except the ability to reach the second Management IP!!!

Please help me!!!

** Feel free to ask some questions to clarify, I attempted to do my best, and my english is not perfect (I’m french)…