Hello,
This behavior usually appears when the Thunderbolt controller gets stuck in an initialization loop after undocking. Here are the steps that are most effective:
• Fully reset the Thunderbolt controller
Shut down the laptop, disconnect AC power, unplug the docking station completely, and wait 1–2 minutes before reconnecting. This often stops the repeated “connect/disconnect” cycle.
• Reinstall Thunderbolt drivers and firmware
For the ThinkPad P53 and the Thunderbolt 3 Dock Gen 2, reinstalling the Thunderbolt driver, Thunderbolt firmware, and the dock firmware (in this order) can restore stable behavior.
• Temporarily lower the Thunderbolt security level in BIOS
In BIOS → Security → Thunderbolt, set the security level to “No Security”, reboot, and check if the issue stops. You can switch it back afterward.
These steps usually resolve cases where the NHI controller repeatedly initializes and the Device Manager refreshes every few seconds.