Off-cpu profiling: broken flamegraph drawn on top of itself

Describe the bug I recorded an off-cpu profile, opened the flamegraph, filtered in on a thread, switched it to off-cpu, and got this garbled mess.

To Reproduce Open the attached .perfparser file. In the flamegraph tab, filter in on RHIThread, then switch to off-CPU time. perf.perfparser.zip

Version Info (please complete the following information):

• Linux Kernel version: 6.16.8
• perf version: 6.16.8
• hotspot version (appimage? selfcompiled?): 1.5.80, from the appimage