There seems to be a problem with the ADD ICON MARKER block. The simple ADD MARKER blocks place the icon in the correct location as demonstrated in this sample project:
https://x.thunkable.com/copy/8c7084463b8b52196b1266af1fcbdc46
When an ICON is placed using the same coordinates, it is always offset by the same number of pixels no matter what the zoom.
Android companion 30304.