Could not enter sub floder

[mengyyy]

Win10 python 3.7 X64
Both these could not get in D:\Test

updog -d D:\\  -p 1920
updog -d D:\  -p 1921

In chrome if get http://127.0.0.1:1920/Test will hit http://127.0.0.1:1920/est

But this work

cd /d D:\
updog -p 1922

[mengyyy]

And

In [9]: !updog -d D:  -p 1989
[+] Serving D:\Downloads\platform-tools_r29.0.5-windows\platform-tools...
 * Running on http://0.0.0.0:1989/ (Press CTRL+C to quit)