Terraform cannot reach registry.terraform.io

Terraform
1

Hey all. We are using TF from the command line and have run into a basic issue sometime in the last month. It used to work but no longer does. This is running from a fairly locked down box and so the issue is likely on our side, just cannot figure it out. For reference, the security team says traffic is allowed to registry.terraform.io (seen as [registry] below). Basic info:

[INFO] Terraform version: 1.10.3
[DEBUG] using github*/hashicorp/go-tfe v1.70.0
[DEBUG] using github*/hashicorp/hcl/v2 v2.23.0
[DEBUG] using github*/hashicorp/terraform-svchost v0.1.1

Very simple main.tf:

  resource "null_resource" "default" {
    provisioner "local-exec" {
      command = "echo 'Hello World'"
    }
  }

Running “terraform init” yields the following error:

…
Initializing provider plugins…

  • Finding latest version of hashicorp/null…
    [DEBUG] Service discovery for [registry] at [registry]/.well-
    known/terraform.json
    │ Error: Failed to query available provider packages
    │
    │ Could not retrieve the list of available versions for provider hashicorp/null: could not
    connect to [registry]: failed to request discovery document: Get
    │ “[registry]/.well-known/terraform.json”: net/http: request canceled
    while waiting for connection (Client.Timeout exceeded while awaiting headers)
    │
    │ To see which modules are currently depending on hashicorp/null and what versions are
    specified, run the following command:
    │ terraform providers

“ping [registry]”

Pinging *.cloudfront.net [18.238.25.104] with 32 bytes of data:
Reply from 18.238.25.104: bytes=32 time=15ms TTL=243
Reply from 18.238.25.104: bytes=32 time=15ms TTL=243
Reply from 18.238.25.104: bytes=32 time=15ms TTL=243
Reply from 18.238.25.104: bytes=32 time=15ms TTL=243

Any help or ideas how to debug further is greatly appreciated.
Thanks!