Cross-measure beaming does not respect full note value when “Display note values across measure boundaries” is enabled

Issue type

UX/Interaction bug (incorrect behaviour)

Description with steps to reproduce

Environment

MuseScore Studio 4.6.4

macOS

Description

The example is from Chopin's Op.28 No.5.

When the option Style → Score → “Display note values across measure boundaries” is enabled, MuseScore correctly displays a note starting near the end of a measure with its full nominal value across the barline (e.g. an eighth note starting on the second half of beat 3 in 3/8). And the duration of this note is correctly recognized as eighth.

However, beaming behavior does not match the displayed note value: The note is displayed as a full eighth note, but when it is beamed together with a preceding eighth note in the same voice, MuseScore renders the beam group as one eighth note + one sixteenth note, instead of two eighth notes beamed together.

This creates an internal contradiction between:

• the displayed note value (eighth note across barline), and
• the beaming logic, which still follows the internally split durations (sixteenth + sixteenth).

Expected Behavior

When “Display note values across measure boundaries” is enabled:

• Beaming should follow the displayed (nominal) note value, not the internally split duration.
• Two eighth notes that visually appear as eighth notes (even if one crosses a barline) should be able to form a normal eighth-note beam group.

Reproduction Steps

1. Create a score in 3/8.
2. Enable Style → Score → Display note values across measure boundaries.
3. In one voice, enter:

• An eighth note on the second half of beat 2.
• An eighth note on the second half of beat 3 (crossing the barline).

4. Attempt to beam the two notes together.

Supporting files, videos and screenshots

In which versions of MuseScore Studio is this issue present?

4.6.4

Regression

I was unable to check

Operating system

macOS 26.2

Additional context

No response

Checklist

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• I have attached all requested files and information to this report
• I have attempted to identify the root problem as concisely as possible, and have used minimal reproducible examples where possible