Two different login screens on Ubuntu 18.10!

So i installed Ubuntu 18.10 fresh install and i did have the normal new login screen of ubuntu gdm3. Ive been downloading gnome themes and i noticed after i did everything(idk if its from installing new themes) when locking the computer i still get the normal lock screen And when i slide it up i get the stamdart login screen:

1. Lock screen

2. Login screen

But now it gets weird when i click on "Log in as another user" i get a new different type of log in screen, which comes when booting into ubuntu after the logo loading screen too(on this login screen the tap-to-click also doesnt work!):

3. 2nd login screen

EDIT: Im sorry i forgot to add a question - What is this(is this normal?) and how to set it back to default?

Added theme: Named "flat remix"

I would be happy for your help Thanks Best Regards!

When the package flat-remix-gnome is installed..
it automatically updates the alternatives for gdm3.css

$ sudo apt install flat-remix-gnome
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following package was automatically installed and is no longer required:
  libfcitx-config4
Use 'sudo apt autoremove' to remove it.
The following NEW packages will be installed:
  flat-remix-gnome
0 upgraded, 1 newly installed, 0 to remove and 36 not upgraded.
Need to get 1,754 kB of archives.
After this operation, 19.8 MB of additional disk space will be used.
Get:1 http://ppa.launchpad.net/daniruiz/flat-remix/ubuntu cosmic/main amd64 flat-remix-gnome amd64 3.30.13-1 [1,754 kB]
Fetched 1,754 kB in 33s (53.8 kB/s)                                            
Selecting previously unselected package flat-remix-gnome.
(Reading database ... 204723 files and directories currently installed.)
Preparing to unpack .../flat-remix-gnome_3.30.13-1_amd64.deb ...
Unpacking flat-remix-gnome (3.30.13-1) ...
Setting up flat-remix-gnome (3.30.13-1) ...
update-alternatives: using /usr/share/themes/Flat-Remix/gnome-shell/gnome-shell.css to provide /usr/share/gnome-shell/theme/gdm3.css (gdm3.css) in auto mode
$

to go back to default.. run the below command and choose the proper value which matches to /usr/share/gnome-shell/theme/Yaru/gnome-shell.css

sudo update-alternatives --config gdm3.css

Example:

$ sudo update-alternatives --config gdm3.css
[sudo] password for maduri: 
There are 7 choices for the alternative gdm3.css (providing /usr/share/gnome-shell/theme/gdm3.css).

  Selection    Path                                                                 Priority   Status
------------------------------------------------------------
* 0            /usr/share/themes/Flat-Remix/gnome-shell/gnome-shell.css              20        auto mode
  1            /usr/share/gnome-shell/theme/Yaru/gnome-shell.css                     15        manual mode
  2            /usr/share/gnome-shell/theme/gnome-shell.css                          10        manual mode
  3            /usr/share/themes/Flat-Remix-Dark/gnome-shell/gnome-shell.css         17        manual mode
  4            /usr/share/themes/Flat-Remix-Darkest/gnome-shell/gnome-shell.css      17        manual mode
  5            /usr/share/themes/Flat-Remix-Miami-Dark/gnome-shell/gnome-shell.css   17        manual mode
  6            /usr/share/themes/Flat-Remix-Miami/gnome-shell/gnome-shell.css        17        manual mode
  7            /usr/share/themes/Flat-Remix/gnome-shell/gnome-shell.css              20        manual mode

Press <enter> to keep the current choice[*], or type selection number: 1
update-alternatives: using /usr/share/gnome-shell/theme/Yaru/gnome-shell.css to provide /usr/share/gnome-shell/theme/gdm3.css (gdm3.css) in manual mode
$ 

About automatic mode and manual mode:

   automatic mode
          When  a  link  group is in automatic mode, the alternatives system ensures that the
          links in the group point to the highest priority alternative  appropriate  for  the
          group.

   manual mode
          When  a  link  group  is  in manual mode, the alternatives system will not make any
          changes to the system administrator's settings.

Source: http://manpages.ubuntu.com/manpages/trusty/en/man8/update-alternatives.8.html