Which model do you have? Under the user guide for the Linkrunner 10G it mentions it does TDR - but the cable should be open/unterminated, not connected.
Although when I cut the blue wire it says good and doesn't show a break unless a wiremapper is on the end...
ALT Uploading Results to Link-Live
The Link-Live upload icon in the app header indicates the status of uploaded or saved test results. Tap the icon to upload manually. See Uploading Test Results and Files in the Link-Live chapter for more information.
Open Cable TDR Testing
LinkRunner 10G can measure the length of a cable and detect some faults by measuring the electrical reflections of the cable using Time Domain Reflectometry (TDR). Connect an open cable (unterminated) into the RJ-45 port on the left side of the LR 10G unit to measure its length and view any shorts, opens, or splits.
When a cable has no detected faults, "good" is shown next to each pair above the length measurement. Cable tests that detect a "split" or "open" in the cable also display the corresponding words.
This unterminated cable test image shows a shorted cable between pins 4 and 7.
Terminated WireView Testing
Using a WireView accessory provides more detailed, per-wire results. A WireView #1 is included with you
ALT Netally 10G link runner showing 5 ft with one blue cable cut
ALT Link runner 10G with a wireview on the end showing the blue cable is broken.