login screen lagging.

[Mad Logic]

After boot or logout, login screen slow to appear, and I cannot type in my password for 4 to 5 seconds after login screen has appeared.

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: lightdm 1.30.0-0ubuntu4~20.04.1
ProcVersionSignature: Ubuntu 5.4.0-84.94-generic 5.4.133
Uname: Linux 5.4.0-84-generic x86_64
ApportVersion: 2.20.11-0ubuntu27.18
Architecture: amd64
CasperMD5CheckResult: skip
CurrentDesktop: MATE
Date: Fri Sep 10 21:37:00 2021
InstallationDate: Installed on 2020-05-05 (493 days ago)
InstallationMedia: Ubuntu-MATE 20.04 LTS "Focal Fossa" - Release amd64 (20200423)
LightdmConfig:
 [Seat:*]
 autologin-guest=false
 greeter-show-manual-login=false
 greeter-session=slick-greeter
SourcePackage: lightdm
UpgradeStatus: No upgrade log present (probably fresh install)

[Marco (marco93)]

I have a similar issue on Ubuntu 20.04 with 1.30.0-0ubuntu4~20.04.1. Sometimes I enter my password, the screen goes black and I have to log in another time. Once lightdm didn't start at all.

If such issues occur I have these entries in the journal:
Sep 12 20:03:10 marco-MS-5455 lightdm[1123]: pam_unix(lightdm:auth): Couldn't open /etc/securetty: No such file or directory
Sep 12 20:03:12 marco-MS-5455 lightdm[1055]: pam_unix(lightdm-greeter:session): session closed for user lightdm
Sep 12 20:03:12 marco-MS-5455 systemd[1]: lightdm.service: Main process exited, code=exited, status=1/FAILURE
Sep 12 20:03:12 marco-MS-5455 systemd[1]: lightdm.service: Failed with result 'exit-code'.
Sep 12 20:03:13 marco-MS-5455 systemd[1]: lightdm.service: Scheduled restart job, restart counter is at 1.