The 5.10.1 image for boundary devices imx.6 contains a /usr/bin/perf that doesn't understand the "--call-graph dwarf" command line option. It will only record call graphs using frame pointers or lbr. This is terrible because it means you cannot use Qt Creator's CPU Usage Analyzer with those images.
The likely cause of this is that the perf in question is not linked against libunwind anymore. The one in the 5.9 images is. perf will only record traces it can also analyze, so it won't record dwarf traces without unwinding support present.