Before anything else, I want to let you know that I’m not very familiar with MikroTik.
I set up a VPN using Quick Set on my home router a few weeks ago. The tests I conducted at home with an iPad connected to the internet via my phone’s hotspot were successful. However, when I tried to connect from abroad (GR) using the VPN, it didn’t work. I also attempted to use my phone’s hotspot and the hotel’s Wi-Fi network, but without success. Strangely, when I returned home and retested, it worked.
What went wrong?
Since there are no psychics with a crystal ball here and we don’t know what exactly and how you configured it, then show us your full configuration
Does your router have a public IP address??
This is what i did in the router Quick Set and ipad. Nothing else.
Address acquisition is PPPoE.
hAP ac
RouterOS 7.15.1
Any crystal ball?
What I would suggest is running the command /export file=anynameyouwish, remove sensitive information like passwords and post the redacted file here because we need to see the full configuration to be able to find out what the problem is
Concur and in the meantime, getting vpn from a broad, is sub-optimal, a direct hookup is far more satisfying 
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