Why is not the useragent the same in both cases?
https://www.whatsmyua.info/ reports the following when I browse with usual Firefox:
Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:96.0) Gecko/20100101 Firefox/96.0
However, browsing with geckodriver reports:
Mozilla/5.0 (Windows NT 10.0; rv:91.0) Gecko/20100101 Firefox/91.0
Here's how I start browsing with geckodriver:
options=Options()
profile_path = '/home/myuser/.mozilla/firefox/x9zoqd7t.default-release/'
options.set_preference('profile', profile_path)
service = Service('/usr/local/bin/geckodriver')
driver = Firefox(service=service, options=options)
driver.get("http://www.whatsmyua.info/")