Slicer not functioning the same on two tables - weird bug

Hi dsj8wksnnckk - The issue arises because conditional formatting in DirectQuery mode generates additional queries that may not respect slicer filters. The best fix is to use measures for conditional formatting instead of applying it directly to columns, as measures are evaluated within the correct filter context.

Instead of applying conditional formatting directly to a column, use a measure to control the formatting logic. Measures are evaluated in the correct filter context.

ConditionalMeasure =
IF(SUM(Table2[Value]) > 100, "Highlight", "No Highlight")

Use this measure in the conditional formatting rules (e.g., background color).

If Table2 has relationships that are ambiguous or bidirectional, use the CROSSFILTER function to force the slicer context to apply correctly.

MeasureWithFilter =
CALCULATE(
SUM(Table2[Value]),
CROSSFILTER(SlicerTable[Key], Table2[Key], BOTH)
)

Hi dsj8wksnnckk ,
When conditional formatting is applied, Power BI sends additional queries to the underlying data source to evaluate the formatting rules. This can sometimes interfere with the behavior of filters or slicers, especially in DirectQuery, where query execution is dependent on the semantic model's configuration and the database's response. So If the conditional formatting is based on a measure, ensure the measure respects the slicer's filters.
For example:

MeasureForFormatting = 
CALCULATE(SUM('Table'[Column]), ALLSELECTED('Table'))