fly deploy resets vm to shared-cpu-1x 256MB

[samuelallan72]

Describe the bug

Similar to #1310

I don't have the number of cpus or vm memory in fly.toml, because I use the same config and codebase for multiple deployments of my app. Each deployment has a different load, so I have scaled them to different vm sizes. However, when deploying (with or without the --vm-cpus and --vm-memory arguments), the app size resets to shared-1x-cpu@256MB.

• Operating system: Alpine linux edge
• fly version: flyctl v0.3.172 linux/amd64 Commit: b389cea BuildDate: 2025-08-25T15:22:14Z

** Paste your fly.toml

primary_region = "syd"

[[vm]]
cpu_kind = "shared"

[build]
dockerfile = "Dockerfile"

[http_service]
internal_port = 8000
force_https = true

[http_service.http_options.response]
pristine = true

[env]
# redacted

** Command output: **

Commands used:

$ fly deploy -a app1 --local-only --vm-cpus 1 --vm-memory 768
$ fly deploy -a app2 --local-only --vm-cpus 4 --vm-memory 1024
$ fly deploy -a app3 --local-only --vm-cpus 8 --vm-memory 2048
$ fly deploy -a app3 --local-only

No output, because no errors, and contains private information.