The text has been put on a path. The issue is when I load the SVG in another tool, the text moves from it's current position to the position of the white box.
Did you put the text on a circle object directly? There seems to be an SVG rendering problem if you add it to a circle object. However, if you turn the circle object into a path by clicking
Object to Path before attaching text to it, the problem disappears.
You can check this svg I made to test the problem. The top circle is a circle object with text on it, but the text disappears when viewing in a browser. The circle below with text on it is a path, and it works fine. If you select the top circle and change it to a path, then it works in a browser. The SVG file is here: http://www.filedropper.com/test_320
This was made with Inkscape 0.92.1
the little square is the baseline indicator (the "line" on which you type text). It's not present on text on path because the "baseline" in that case is the path.
It's graphically shown because it's snappable "snap text anchors and baselines" and alignable with others baselines in the align and distribute panel
(in the case of text on paths, it should not exist or be placed at the beginning of the path, but it seems to be placed at (0,0) for some reason)