Cubase 10 Pro - Flattening the arranger track removes all the Layout Layer text (in Score Editor)

Cubase
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1

I’ve attached to this message the CPR file. Open it, flatten the arranger track, then notice that the Project Layer text stays put, while the Layout Layer text disappears. What can I do to stop this from happening?
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Flattening arranger removes layout layer text.cpr.zip (15.7 KB)