Chrome Version       : 54.0.2840.99 (Official Build) m (64-bit)

URLs (if applicable) : our web application 
(https://reporter.salesapex.com)

Other browsers tested:

FF OK 49.02
Edge OK 20.10240.17146.0

have tested this issue:
     Safari: No
    Firefox: Yes
         IE: Yes

What steps will reproduce the problem?
When you open a drop down box, which is really a div with overflow set to auto, there is normally a scroll bar when in desktop mode that appears when the content overflows in the vertical direction. 

What is the expected result?
Expect to see a usable vertical scrollbar in drop down box.

What happens instead?
Chrome thinks it's in tablet mode and does not display a normal scroll bar and does not allow mouse to scroll down. 

Please provide any additional information below. Attach a screenshot if
possible.
I put Chrome into table mode by changing the Enable Touch Events in the Chrome Flags and was able to reproduce the issue. It seems the browser thinks it's in table mode whether it really is or not. Maybe you are incorrectly interpreting the OS call to check for that setting. FF seems to work fine. Edge works fine. This issue didn't exist a few days ago. Also it seems to be related to Windows 10. The laptop is a Lenovo which converts to a table. Does not occur on a Lenovo laptop running Win 10 which does not convert to a table.