Remote Control disconnects after a few seconds (regression ~March 7-8)

Environment: Windows 11 Home 10.0.26200, Claude Code v2.1.72, Wi-Fi connection

Issue: Remote Control sessions disconnect after a few seconds. Was working perfectly ~3-5 days ago, started dropping consistently without any changes on my end (no CLI update, no network changes, no OS updates).

Symptoms:

• Session connects fine initially
• Drops within seconds — sometimes silently (messages appear to send but never reach the CLI)
• Refreshing the page sometimes reconnects briefly, then drops again
• No error messages on the CLI side — it just goes quiet

What I've tried:

• Confirmed on latest CLI version (2.1.72)
• Wi-Fi adapter power management is not throttling (shows "Unsupported")
• Applied TCP KeepAlive registry fix (30s instead of default 2hr) — hasn't resolved it
• No firewall or antivirus changes

Timing suggests a server-side regression — nothing changed locally, it just stopped being stable around March 7-8, 2026.

Related issues: #28532, #28571, #29219, #29855

Would be helpful to know if there were any relay infrastructure changes deployed around that date.