play sound bug very long musicxml, visual design, this form

original
https://flat.io/score/5f466bf04e2eb625792989c8-yin-le-li-lun-nofa-ze-ma…
musicxml file exchange out put
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musicxml play on MuseScore 4
very unnatural sound
notes in sheet music and MIDI sounds are not linked

MuseScore 3.6 + 32 bit Windows 7
MuseScore 4 + 64 bit Windows 11
same result

other test
REAPER → broken MIDI
Dorico SE 4 → correct sound
but, do not view many vertical line
Japanese text「和音」 → Latin text "XXX" text changed, rehearsal mark

I does not have uploaded musicxml file, my desktop. by drag and drop.
7MB.

other
Drag palette tab to float
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Move to other position
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Tried to merge tabs by dragging them to the original palette
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Tabs did not combine with others
(Reference: Adobe Illustrator, Photoshop versions from 25 years ago)

visibility
For dark / light mode + high contrast UI
I specified "emphasis color" as an absolute value, but it is displayed in a state where black / white is mixed in buttons and menus.
I calculated the contrast, hue, saturation and luminance to specify the emphasized color, but MuseScore changes the color value on its own. This is a nuisance.
Other color modes give even worse results. This is because background gray and translucent processing are applied. The characters in the buttons and menus are black or white, but the contrast between the colors adjacent to the characters and the background is reduced, making the characters invisible.
Concessions, the UI is better compared to version 3.

https://musescore.org/ja/node/add/project_issue
this page
file upload
drop once
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was it uploaded? I cannot see it, so I do not know
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Add, upload later
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previous upload lost
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Click "Save" button
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It took hours to write this sentence
Click "Save" button
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All text and uploaded files disappeared
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I see
"There are items that have not been entered!"
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I compleated input text
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I can "save"

upload files 8 items

thank a lot.
私の英語は間違っている可能性があります。すみません。