Need Help w/Lockscreen Win10

My monitors resolution is 3840 x 2160 & yet I can't get a lock screen pic to adjust right. It's all blurry & out of focus. I've tried smaller resolution pics to & even tried both fill & fit & I've even resized an image to 4.3 ratio & NOTHING I mean NOTHING WORKS !! When I make adjustments in windows default picture viewer & save it I press windows key + L to view it to see if it's correct & IT IS !! but if I restart that's when it's all messed up. Would like a solution to this problem. OH & yes I do have dual monitors but not of the same size & YES I unplugged 2nd monitor (TV) they are both TV's.

Win10 Pro
22H2
Installed 5/27/'23
OS.Build 19045.2965

I think this tutorial may help,

Enable or Disable Acrylic Blur Effect on Sign-in Screen in Windows 10

Thank u that was it & took no time to fix. Thank u so much.

You are most welcome.