There seems to be a newly formed issue in displaying (?) XYZ tiles in QField.
In preparing a project in QGIS (desktop) I have for perhaps the last year successfully viewed XYZ tiles in QField after having added tiles in to a QGIS project via the directions outlined in the answer of @MatthiasKuhn (~3rd answer from the top) to this post: Adding Basemaps from Google or Bing in QGIS?
(See also: https://www.lutraconsulting.co.uk/blog/2016/10/26/qgis-xyz-tile-wmts-preview/)
However, recently the XYZ tile layers, while working fine on the desktop, do not either display or copy over in or into QField. (they do seem to be listed in the QField application's legend, though they are "greyed out")
I have usually used the QConsolidate plugin to transfer my project, but have now tested with the QFieldSync plugin also.
If the methods described in the linked answer above are no longer a successful way to access XYZ tiles (such as google satellite) in QField, what is a current way to access XYZ tiles in a QField project?
[could the web addresses for the tiles just have changed?]
Using QField 10.4 - Kesch on Android 5.1.1 from a project prepared on QGIS 2.18.15 (Win 7).