From my experience it's not a glitch, ff Dev tools are slow and second class compared to chrome.
Quantum made it viable to use ff on my old laptop, but a daily driver for a web dev it still is not.
This, and especially perf profiler is lacking in every way compared with Chrome
I did experience a glitch the other day in dev tools where a pane blanked out on me. I may have had a crash too, but that's it.