Rendering issue with Greek characters

[westnordost]

TO REPRODUCE THE ISSUE, FOLLOW THESE STEPS:

Display the text "Σπιτική"

RESULT:

A text that looks something like "Cπιτικη´" is displayed.

EXPECTED RESULT:

"Σπιτική" is displayed

ENVIRONMENT:

• Android
• tangram-es 0.17.1
• Font: Roboto (Android system font that does support Σ and ή, see screenshot below)

[westnordost]

Note: The same with Cyrillic letters

[mnalis]

(nitpick: note that this picture shows Latin script, not Cyrillic. But some letters have caron and acute on them, which are more or less working like umlauts in German).

But their rendering is broken, yes.