When trying to login, I cannot select my account by tapping on it, it feels broken until I find out to press through the trackpad until it makes a cracking noise. I assume the cause is that the default input setting (for not logged in / all users / new account) disables "tap to click". 

I don't know if this default is introduced by gdm, the input manager or the distribution (however Ubuntu Unity enables it by default), but I think there are reasons it should not be default like that.

1. Disabling by default "tap to click" causes inconsistency, surprise or frustration for users who have this enabled within their own account, but are unexpectedly exposed to the default before logging in.

2. The default (for session login etc.) should be all-encompassing rather than specialized/restrictive. A user who prefers to click is not hindered by tapping being enabled. A user being used to tap is however hindered by tapping being disabled. New users coming from other systems should not encounter Gnome/Linux seemingly "broken" or "this works only one way" if it could work all the ways.

version: gdm3 3.24.1
system: Ubuntu Gnome