Nix develop HTTP error from binary cache

Recently, one of the substituters on my NixOS machine has started failing when I run nix develop. The error message is as follows:

warning: error: unable to download '<hash>!out.doi
HTTP error 500

What I’ve tried (Error persists):

  • Upgraded to the latest stable version of Nix (24.05)
  • Rolled back to a known working state
  • Ran nix collect garbage
  • Turned off custom DNS service

What works:

  • Simulated in VM (Ubuntu running with Nix) from the same host machine (so network might not be the issue?)
  • Removed the failing substituter (Though this is not an optimal solution)

Has anyone else encountered this issue? Any suggestions on further steps to locate the root cause would be greatly appreciated.