I noticed this screw dangling down behind the strings. I believe it is a perimeter plate bolt. I can not speak very highly of the quality of non-Japonise Asian made pianos. Maybe it was made on a Friday afternoon.
Certified piano technician. North Bennett Street graduate. In business since 2003. Specializes in vintage electric pianos (Rhodes, Wurlitzer electric pianos). From a standard tuning to a complete rebuild - pianos by jay does it all. Shop located in Somerville, Ma.