I have had windows 10 installed on an external hard drive for a few months. I use bootcamp on my macbook pro to switch between macos and windows. Usually I can restart my computer while holding the option key and the 2 boot drives will come up and I can choose between the two and it will work fine. I tried my usual switch today and both boot drives showed up but when I chose the Windows 10 boot drive the screen froze and it booted up in macos anyway. The external drive is showing up in macos but I can't switch to it. Any thoughts?