Sleep from Quick Action does not load book cover

[Tabascode]

Device

X3

Affected Version

1.5.1-rc3

EPUB Optimization

Yes, using a different EPUB optimizer

Cache State

No / Not Applicable

Describe the Bug

Sleep wallpaper ist set to "Cover"
Cover Mode: Fit
Cover Filter: Off
Quick Resume on Timeout: Off

When I enter sleep mode through Power Button long press, all works as expected (cover shows up).
When I go through quick actions (set to Power Button short press), the device goes to sleep, but the screen does not change, i.e. the current page is still visible.

Steps to Reproduce

(see above)

Expected Behavior

(see above)

File Provided

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Relevant Log Output/Screenshots