The same might be true if you’re behind a CG-NAT. (But if the canyouseeme check worked then you’re probably not.)
Either you have to adjust your network configuration so that incoming connections work properly (usually not possible when using the official apps of these “VPN” providers, but can work if you set everything up manually) or just stop using it completely. Some of these providers might also offer port-forwarding, how it is configured would depend on the provider / their implementation.