Just a couple of quick questions to help out,
1. The hosted tile layer is in AGOL or in ArcGIS Enterprise?
2. Can you provide the URL of the print service you configured?, Is it your own or an Esri hosted one?
The print widget will create an ExportWebMap object which it will send to the print service. Generally when a layer doesn't appear in the output, its because the print service cannot access the layer.