Hi there
I would also leave it longer
Is it blocking the tube and has she been in the cage long? It can take them a while to decide on their habits and nesting. If they feel there isn't enough space under their nest for a hoard then they can look for somewhere else to do one. Our hamster currently has a second hoard in a little ceramic hideout.
Maybe give it a bit longer and see if her habits settle out. I also feel it would help if you were to post a photo of the set up. Looking at that helps see what may lead to certain behaviours. Surprised the guinea pig house wasn't used! Maybe location?
Their basic instincts are nesting, hoarding and foraging. So if they have plenty of substrate under the nest they tend to bury hoards under the nest. If they have minimal substrate under the nest they may look for other places and have a few little hoards elsewhere.