Amazon web services – AWS EC2 instance is pushing an HTML file on port 8000, but I can't view it from my local browser

I am by no means an AWS or networking/server expert, so please forgive my ignorance in the description below.

I currently have a Flask app running inside a Docker container within an EC2 instance, but cannot view it externally in a web browser when going to the EC2 instance’s public IPv4 address (either http or https versions, with and without the :8000 port indicator). When I SSH into the instance and do curl localhost:8000 it shows the whole HTML document as expected, which makes me think that it’s an EC2 issue and not a Docker issue (otherwise curl in EC2 would not show the HTML script, right?).

In the security group assigned to the instance, I have the outbound rules set to all for Type, Protocol, and Port range; with destination as 0.0.0.0/0. For inbound rules I have HTTP>TCP>80, HTTPS>TCP>443, and SSH>TCP>22, all with Source of 0.0.0.0/0.

In case it matters at all, the EC2 instance is based on an Amazon Linux 2023 AMI with ARM64 architecture (to match the docker container created on a Mac). The Docker container runs Ubuntu 22.04 and Python 3.10.12.

At this point I’m completely lost. I don’t know what I’m missing, but obviously it’s pretty crucial for being able to see the app. Any help or suggestions would be greatly appreciated.