I have the same problem 
The filter by IP address is activated in administration :
With the debugger I have “Excluded event” :
but when I check the statistics with a segment that excludes the same IP address I have a difference in statistics (vs. all visitors) :
Hi. The IP filter works from the moment it was implemented. Segmentation works right away. Try to check the same data today or tomorrow (if you implemented the change today).
Hi,
the filter was implemented several months ago.
I think there is a problem on the segment too, here is an example of the statistics from yesterday:
it is not possible to have 3000 difference visitors by filtering our IP address (it is our internal IP)
Thanks
I need some more info here. Do you use IP masking? Keep in mind that we by default drop the last part of IP address in reporting. Could you paste full screenshot with the IP address included (you can fake it, just want to see the format you’re using).
Also, after applying the segment, you can check the session log if displayed sessions match your filter.
Yes I use IP masking :
looks like: xxx.xx.xx.xxx
I also tried this segment but I have the same result :
Hi. Masking is one problem and I guess you know it already. Other problem is that your website might also have traffic from visitors using ipv6. In this context, your ipv4 filter might exclude also those visitors.
Try this one out. 
OK 
Thank you
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