How to reproduce:
1. Create a new project
2. Open the Profiler window (Window -> Analysis -> Profiler)
3. Load the attached Profiler data (timeline-selection-highlight-bug.data)
4. In the Profiler Modules drop-down select only 'CPU' Module to be displayed
5. In the chart select the last frame (300)
6. Make sure the Profiler display is set to 'Timeline' (use the top-left dropdown in the details panel)
7. Make sure the 'Show Full Scripting Method Names' option is disabled (there's an 'additional options' drop-down list in the far right of the details panel)
8. In the Timeline panel select GUIUtility.ProcessEvent() sample

Expected result: the chart highlights frames 283, 300
Actual result: the chart does not highlight any frames

Reproducible with: 2019.3.14f1, 2020.1.0b9, 2020.2.0a11
Could not test with: 2018.4.23f1 ('Show Full Scripting Method Names' option not introduced)

Workaround:
Enable 'Show Full Scripting Method Names', then deselect and select GUIUtility.ProcessEvent() sample again

Notes:
The issue occurs only with scripting methods (blue samples)