Eternal Arena – While transmuting may rare equipment into epic, why was the level increased but the stars weren’t?

When rare equipment is transmuted into epic equipment, the level will be transmuted but not the stars.

You can find the related information in Point 3 of the ‘Info’ in Transmuting, which says ‘if the transferee has no stars and is of the same grade as the transferor, it will receive the transferor’s stars.’