Energy sankey background disappears after a while

[yosilevy]

Checklist

• I have updated to the latest available Home Assistant version.
• I have cleared the cache of my browser.
• I have tried a different browser to see if it is related to my browser.
• I have tried reproducing the issue in safe mode to rule out problems with unsupported custom resources.

Describe the issue you are experiencing

My configuration:

type: energy-sankey
title: Energy flow
layout: vertical

The view loads file but after a while of letting the browser just sit there (going to other apps and then back to the browser after a meeting (few minutes - hour), most of the background disappears as you can see below:
Initial:

After a while:

Describe the behavior you expected

It should stay the same regardless of the time

Steps to reproduce the issue

1. Create a dashboard with the energy-sankey card
2. Open dashboard
3. Switch to another app
4. Wait a few minutes/hour
5. Go back to HA

What version of Home Assistant Core has the issue?

2025.1.4

What was the last working version of Home Assistant Core?

No response

In which browser are you experiencing the issue?

Edge

Which operating system are you using to run this browser?

Windows 11

State of relevant entities

Problem-relevant frontend configuration

Javascript errors shown in your browser console/inspector

Additional information

@MindFreeze - please take a look

[yosilevy]

It also just happened when I came back from sleep mode (causes partial window refresh).

[MindFreeze]

Can't reproduce on Chromium. Will try Edge but I'll probably be refactoring this whole card soon so won't bother fixing this now

[MindFreeze]

Looks like Edge doesn't like the gradientTransform attribute. Can be replace with x1,x2,y1,y2 in theory