I really need to learn how to work with percussion in Dorico

Please don’t bump threads. As much as I understand issues can be frustrating, you last had a response from Daniel yesterday. Please be patient, as members of the development team generally offer their insights here in addition to their duties elsewhere.

Have you done things like double-check the bar rest in bar 14 isn’t explicit for the Xylophone? Played around with deleting and re-inputting notes in the bars either side of bar 14?