@Viet001 :
Hi there,
I tried to create a KLWP preset based on your description here. The result is the background image is always changed by the trigger.
Screencast: TIP • Random Background
If it is not the same as yours, please share some screenshots of your KLWP preset with us so that we can help you troubleshoot the issue.
You can upload/attach the screenshot cukes here, or alternatively you can upload them to your Google Drive and share them with us here.
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