segaufo.cpp- BGM cannot switchable by DIP switch

[pizzzza19]

MAME version

0.270

System information

Windows 11
Intel Core i7
Nvidia GeFore RTX

INI configuration details

No response

Emulated system/software

segaufo.cpp / UFO catcher 21

Incorrect behaviour

DIP1-1: 1 coin as 2 PLAY
DIP1-1: 1 coin as 3 PLAY, 2 coins as 6 PLAY, 3 coins as 9 PLAY
DIP1-4: 1 coin as 6 PLAY, 2 coins as 9 PLAY
DIP1-8: 2 coins as 1 PLAY, 3 coins as 2 PLAY
DIP2-4: Advertise BGM NORMAL #2 ? ON
DIP2-8: Advertise BGM NORMAL #1 ? ON
DIP2-10: Advertise BGM CHRISTMAS ON

Expected behaviour

DIP1-1: 1 coin as 2 PLAY
DIP1-1: 1 coin as 3 PLAY, 2 coins as 6 PLAY, 3 coins as 9 PLAY
DIP1-4: 1 coin as 6 PLAY, 2 coins as 9 PLAY
DIP1-8: 2 coins as 1 PLAY, 3 coins as 2 PLAY
DIP2-4: Advertise BGM NORMAL 2 ? ON
DIP2-8: Advertise BGM NORMAL 1 ? ON
DIP2-4 & DIP2-8: Advertise BGM CHRISTMAS ON This contains several songs
DIP2-10: TIME ATTACK short?
DIP2-20: TIME ATTACK long?
DIP2-40: Unknown
DIP2-80: Unknown

Steps to reproduce

While DIP2-10 is ON, any of DIP2-4, DIP2-8 combo will cause Error beep.
2-10 + 2-4 = Error
2-10 + 2-8 = Error
2-10 = Christmas

Additional details

Not sure all of the combo of DIP SW but it looks like DIP2-4 / DIP2-8 / DIP-10 will work for BGM control.