Something like /api/apps/?q=ai&num=20&fullDetail=true will return "Cannot read properties of undefined (reading 'length')". Removing fullDetail=true works.
I have a hunch that it is only for queries larger than a certain size (actual result count; using num does not fix). E.g., /api/apps/?q=game&num=20&fullDetail=true works as expected with additional detail.
Not sure if this API issue or something with the underlying package. There are similar issues though (this with the "similar" endpoint).