It looks like a serious race condition. Compare these alternatives:
All of them are files with a valid SVG content (Base64 embedded). If the first SVG file is slightly modified, it is displayed correctly. But this solution turned out to be very weak and dependent on many factors:
Apply diff to the original SVG files (before embedding):
(2) http://drifted.in/other/planisphere_printDefault_correct_01.svg - fixed using two digit label
(3) http://drifted.in/other/planisphere_printDefault_correct_02.svg - fixed by removing decimal points in the rotate angle
When a minimal working example was prepared, that bug disappeared very often by removing just part of text. E.g. removing the embedded font in the CSS part, removing the URL address in the cover, almost any change had an impact on this behaviour. So I preferred files without large changes inspite of being bigger.