Line chart where data points has no colors

[NunoTrigo1986]

I created a line chart in Power BI using a union of two tables: one containing a normal measure (legend) with several data points over time, and another with the same structure but where the measure (legend) has only a single data point.

In Power BI Desktop, everything works fine when I select the legends I want to display. However, after publishing, the measures with just one data point lose their color. Interestingly, if I hover over the timeline they belong to, the color temporarily appears while hovering.

Is this a bug? Is there a way to fix this issue?

pictures 

all the data points on the table are on the chart. although they are not visible BUT, if i touch  with a mouse on the right time line, they appear :

[rajendraongole1 · Accepted solution]

Hi @NunoTrigo1986 - In Power BI Desktop, line charts render single data points as small dots or markers, and the legend retains the color for those points.
After publishing, Power BI Service sometimes fails to render single data points consistently. The color in the legend or chart may temporarily reappear during interactions, such as hovering, but it does not persist.
Line Chart Limitations:

Power BI assumes line charts represent continuous data over time. When a legend contains a measure with only one data point, it may treat this as incomplete and fail to render it correctly unless there's user interaction.

1. Force Consistent Display Using Marker Shapes
Enable markers for the lines in your chart. This ensures single data points are visually represented, even if there’s no line connecting them.
Steps:
Select the line chart in Power BI Desktop.
Go to the Format Pane → Shapes → Turn Show markers to On.
Publish and test the report again.
2. Add a Dummy Data Point
To address the issue of single data points, you can add a dummy data point to the dataset so that each legend item has at least two data points. This makes Power BI treat it as a continuous series.
Example:
For a measure with one data point (e.g., "3/1/2019"), add a duplicate row with a different timestamp but the same value.
3. Switch to a Different Chart Type
If adding dummy points or enabling markers does not work, consider switching to a scatter plot or similar visual, which handles single data points better than a line chart.
4. Check Compatibility and Updates
Ensure your Power BI Desktop version and Power BI Service are updated to the latest version. Microsoft periodically fixes rendering bugs in updates.

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