Created attachment 171246 [details]
Example of unexpected flood fill behavior (filling the rectangle with orange)

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SUMMARY

When using the flood fill tool to fill in a shape (black border, white interior. Relatively certain this occurs with other borders/fills as well), the tool does not fill in the entire shape. Instead, it appears to draw a horizontal line where the cursor is, and fills in the portion of the shape that is above that horizontal line. Filling the shape with an alternate color and then refilling with the target color appears to resolve the issue and allow the flood fill to correctly fill the entire shape, although it should be noted that doing this many times will cause the issue to return as well (which will then go away again when you fill-and-refill). This appears to be unintended behavior.

STEPS TO REPRODUCE
1. Draw a shape with a black border and white interior
2. Attempt to use the flood fill tool to fill the interior of the shape with a 3rd color

OBSERVED RESULT

Flood fill only fills a portion of the shape

EXPECTED RESULT

Flood fill fills the entire shape

SOFTWARE/OS VERSIONS
Windows: 
macOS: 
Linux/KDE Plasma: 6.9.3-surface-2 (64-bit)
(available in About System)
KDE Plasma Version: 6.1.1
KDE Frameworks Version: 6.3.0
Qt Version: 6.7.0

ADDITIONAL INFORMATION