Lock Screen doesn't respect screen size for the greeter background in multi-monitor configuration

Hi.

I have a dual-monitor hardware (notebook+monitor).

I noted that the screensaver shows the greeter screen on the monitor where the cursor was before activating the screensaver. And the background image and it's size are from the main monitor, not the monitor where the greeter screen is shown.

Is there a way to fix this? Thanks.

An example screenshot is attached. It was taken from the second monitor. The picture has the size of the first monitor which is the notebook. The screens have different size and background images.

Update: completely removed lightDM and installed SDDM. Now I see, that the screensaver uses it's own greeter. So I modified the topic and description.