Support for initial setup in AWS with Transfer Family

Dear Community

I'm trying AWS for our company and managed to learn already some stuff! Right now i'm trying AWS Transfer Family for SFTP and created a VPC with subnets, a security group, a IAM profile for permissions on my created s3 bucket.

I setup everything. The server is online and i added a user aswell the public key.

Under Endpoint details i see the status online, the endpoint type, the vpc, the endpoint itself and "internet facing". Aswell under endpoint configuration the availability zone, subnet id, private ipv4 and the public ipv4.

When i try to connect to the endpoint with the public key, i always getting following error ""Resource temporarily unavailable" and "connection closed". I allowed as a inbound and outbound rule port 22 from the whole internet (to test it) but still not working.

What do i missing?

Thanks a lot and best