When Curl Works but IntelliJ Doesn't: The Ollama Connection Mystery

Summary

I run a bunch of internal services through Traefik on my LAN, each with a proper domain name and TLS, so I don’t have to remember ports. One of them is Ollama, sitting on a beefy gaming PC at 10.0.0.105 and exposed as https://ollama.tymscar.com. From the terminal everything behaved exactly as expected: fast responses, certificate valid, models listed. Then IntelliJ IDEA decided this host basically didn’t exist. The “Test Connection” button just said “Failed to connect”. No detail. No hint. Just a smug little red failure.Meanwhile:curl -s https://ollama.tymscar.com/api/tags | jq '.models[].name' | head -n 4 "gpt-oss:20b" "llama3:8b-instruct-fp16" "qwen3:32b" "Supa-AI/mixtral-8x7b-instruct-v0.1:q4_k_m" And the plain internal HTTP endpoint (skipping Traefik entirely) also worked:curl -s http://10.0.0.105:11434/api/tags | jq '.models[].name' | head -n 4 "gpt-oss:20b" "llama3:8b-instruct-fp16" "qwen3:32b" "Supa-AI/mixtral-8x7b-instruct-v0.1:q4_k_m" So networking, DNS, TLS termination, Ollama itself: all fine.False Start #1: “Maybe IntelliJ just doesn’t support HTTPS here”#Not a wild idea. I’d already hit a similar limitation months before with Raycast’s Ollama support. I even tweeted about it at the time. Raycast was hardcoded to use plain HTTP for Ollama, so when I tried an HTTPS homelab endpoint it mangled the URL into something like http://https://myDomain and App Transport Security then blocked the non-local HTTP fallback. So the idea that IntelliJ might also just not support the HTTPS reverse-proxied variant first didn’t feel far-fetched.So I bypassed Traefik completely and pointed IntelliJ straight at http://10.0.0.105:11434. Exact same failure dialog. So not HTTPS.False Start #2: “macOS local network permission?”#Checked System Settings > Privacy & Security > Local Network. IntelliJ was already allowed. Nothing to toggle. Still failed.False Start #3: “Firewall?”#macOS firewall off. No third‑party blocker. Another dead end.At this point the pattern was clear: if cu...