My bad I misread your post. If GPT4all didn't work out, go with Aider. It’s a CLI tool, doesn't have a UI trying to proxy requests to a dev's server. You just point it at your local model (via Ollama or vLLM) and it stays in its lane. Since it’s Python-based, you can grep the source code to confirm there are no hidden update pings. If that's not for you, and you need the IDE experience, pick Continue. It’s the only one that handles air-gapped setups properly. You can manually install the .vsix file and kill all telemetry in the config.json. Unlike OpenCode, it doesn't try to be it’s just a bridge between your code and your model server. OpenCode failed because it’s basically "cloud-first" pretending to be local. Aider and Continue are actually built for what you want.
From what I know of, Ollama works offline, but if your ram is only 8 GB and without a GPU, latency would be severely limiting. The closest local model I can suggest is LM Studio (no cloud dependencies, own model registry, etc.). If that doesn't work out for you then GPT4All, but its models are quite small.