Lineage 17.1 - FP2

[Alex.A]

It was mentioned in may already:

@_Chris

I updated LineageOS to 20200529 yesterday morning. Since then the time set in Settings > Security > Screen lock > Lock after screen timeout doesn’t have any effect any more. The screen is locked immediately when the display turns off after screen timeout (Settings > Display > Screen timeout).

I myself can confirm what you experience.