He is what I understand:

During the summer, Netskope implemented a change to address a problem when companies merge.   Apparently if two companies merged but two computers had the same hostname (?) they would have duplicate client ids.  

I typically run a report of a month's worth of devices when we upgrade versions.  I run it daily to watch the increase, watch to see version change over time, and to find orphan machines that refused to upgrade their version.

After the change, I immediately noticed about 2X the number of computers I have.  It turns out that in addition to changing the ID, they also changed the download options, where before it had dialog option to choose whether you wanted everyone that has logged into a machine or just the last person, now there is no option.

 So now when downloading the list of machines, one to use Excel to deduplicate hostnames.  But it still isn't a good solution, as you don't necessarily get the right last reported date.

So far Netskope's response to this paraphrased "We don't see the problem with the client doing the extra step of deduplicating their data" and to deny changing the dialog box of download device data.

First, I wanted to make people aware of this phenomena as not to have errant data reports.  Second, if your tenant is doing this, I would appreciate you reporting  (if you feel it a problem too) so that Netskope takes it more seriously.