Online Screen Saver refresh problem

Hi there.

Thanks to everyone who has contributed towards the plugins in question. I am having some trouble with the Online Screen Saver. I was hoping maybe someone could point me in the right direction.

I am using a PW2 5.12.2.1.1.

I am updating a single PNG image from a Firebase storage bucket that overwrites the 'bg_ss00.png' in the 'screensavers' folder. The image renders correctly on first load, but when it refreshes it renders a black rectangle over the top two thirds of the screen - which does show some of the updated image data.

The image is being rendered using HTML5 canvas and creates a base64 url that get's encoded to a PNG file (768 x 1024).

I'm not sure if this is something I am doing wrong with the encoding of the image, or some eips config that I need to tweak.

Thanks.
Gareth