I can reproduce the problem in a ppc64el cloud instance, and it can be observed in firefox's autopkgtest results, too (http://autopkgtest.ubuntu.com/packages/firefox/focal/ppc64el).
The problem is not a version mismatch though. The firefox-geckodriver package is built from the same source package as firefox, and it works on other architectures.
I can reproduce the problem in a ppc64el cloud instance, and it can be observed in firefox's autopkgtest results, too (http:// autopkgtest. ubuntu. com/packages/ firefox/ focal/ppc64el).
The problem is not a version mismatch though. The firefox-geckodriver package is built from the same source package as firefox, and it works on other architectures.