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.
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.