11815.4 seconds = 197 minutes (approx) = 3 hours? Is that how long it takes?
where is the slowness, before the login screen or after?
Bios start up time in Task Manager represents the time it takes the motherboard to hand control of PC to windows 10, if it is really long it can be a sign hard drive is problem.
What hdd do you have?
Can try running start up repair and see if that helps
Go to settings/update & security/recovery
Under advanced startup, click restart now button
this loads a blue menu
choose troubleshoot
choose advanced
choose start up repair - this will scan PC and maybe fix this - will ask for logon info