Cursor becomes smaller in Office apps.

I have the same problem (still not resolved) along with other display problems.  All took place after a Window 10 update to version 1709 on December 23, 2017.  I have a Dell XPS laptop connected to a docking station and two monitors.  It was fine before the update, but now window size are disrupted all the time and the cursor problem started happening.  See below for other the other display problems - large fonts.

I concur with you. 

I never had this odd issue when I was running these computers on 1600x1200 at 100% scaling.  When we upgraded to monitors running 3840x2160 with 150% scaling we started to see the problem.  So, (being one of the earliest people on this thread and the thread this was split from) I still suspect that it is an issue with scaling, resolution, and possibly mouse driver. 

It is a daily annoyance.

Further update...

Once I have resolved this issue as per my own instructions further back in this thread, it continues to work fine while I only use my laptop attached to external displays, which are HD, which for the most-part is what I do.  The problem recurs once I use the laptop display itself, which is UHD, which I suspect is part of the problem.

Simon.

Just received my first ticket from an end user with this same issue. The error started with setup of a new computer (Surface Pro 4), I have the users old computer (also a Surface Pro 4) which does not have the issue. The last update the the old computer received was at the end of September. The new Surface has all the current updates and drivers.

My shrinking cursor issue has magically disappeared.  I wish I could say I fixed it but alas, all I have done is keep working. I'm sure my laptop has been through several reboots and different monitors since I posted my screenshots above.  Right now scaling is at 100% on my dual 1920x1200 monitors and all is fine.

If the problem re-appears I'll let you know.  

You know what...so has mine!  Not going to consider this as fixed just yet though as it may return.  Will let you all know.

Simon.

An update in case it helps...

So, my issue had appeared to have gone away since the New Year, until about half an hour ago when it appeared to returned while I was in the middle of amending a Word document.  I am using tables and noticed that the mouse pointer was disappearing when it should have been displaying a cursor positioning symbol within a table cell (I have noticed this before within this whole issue but usually when using RDP software).  I also noticed the column resizer pointer had shrunk.  I moved my pointer to the left of the main document so it was off the document, this being my usual quick test to see if the issue exists, and it was fine.  I went back to the other areas of the document to see how the pointer behaved and it was all wrong.  When I moved off document again, the arrow pointer had shrunk.

My method of changing the scaling and logging in and out has fixed it, how long for we will have to see.

Simon.