8vb in lower staff of a piano grand staff?

I’m having trouble getting an 8vb to work on some very low notes I’m writing for piano. Both 8va and 8vb seem to work for me only in the higher (RH) staff. Has anyone else experienced this issue? What am I doing wrong?

Thanks!

Is this cross-staffed material? If so, invoke the caret, then use the down arrow on your keyboard to get down to the lower stave, then type Shift+C 8vb (or 8va) Enter. You’ll need to then hit Space bar to extend the line, and it might not appear at all until you’ve hit Space bar once.

No, it turns out that I just needed to restart my computer. It wouldn’t do ANY clef changes in the LH, thus the give away that I needed a complete reboot.

Thanks!