FTP Not Working when using static IP

I’m in the newbie camp here, so be kind.

I’m running a VM on GCP with a reserved IP. The FTP client will not connect using FTPTLS. This was the case for CP 20.0 and 20.1. on Ubuntu 18 and 20.

I switch my IPs to ephemeral and it will connect.

What causes this, and how would I be able to fix it?

I should mention that I was using Filezilla. I’ve tried many combinations of firewall states (local and server side).

Thanks. I’ll reach out to them, but seems very strange since my GCP firewall had no changes between the two IP options. FTP would only work with the ephemeral IP address.