Have you tried booting the laptop into Safe Mode (with networking)?
If you get the expected (faster) connection speed in Safe Mode, then it strongly points to either the network drivers (or some other software being loaded as part of your standard startup) that is causing the slow connection.
How to boot into Safe Mode - https://support.microsoft.com/en-us/windows/start-your-pc-in-safe-mode-in-windows-10-92c27cff-db89-8644-1ce4-b3e5e56fe234
If you get the expected (faster) connection speed in Safe Mode, then it strongly points to either the network drivers (or some other software being loaded as part of your standard startup) that is causing the slow connection.
How to boot into Safe Mode - https://support.microsoft.com/en-us/windows/start-your-pc-in-safe-mode-in-windows-10-92c27cff-db89-8644-1ce4-b3e5e56fe234