Arpeggiator ''Speed'' setting always greyed out (Inactive)

[Kostas Ketseris]

Hello, I am a new owner of a Yamaha PSR-SX 900 from Greece with no previous experience with any arranger or keyboard. I had a band since 1996 where I played guitar, sang and do the songwriting. Now at 50 I have decided to buy an arranger to continue at home and you have helped me a lot with your site and forum so congratulations on your great work. So I'm asking you to  show some sympathy if my questions seem stupid!

I would like to ask why in the arpeggiator settings the "speed" option is always grayed out and inactive. I understand that it follows the tempo of each style but I think it would be very useful to be able to bring it where you want. Thank you very much!!