Some SVG images with non Latin text such as Chinese or Japanese when uploaded to Wikimedia, the non Latin text in the PNG render turn into tofu glyph completely. This issue happens very randomly. Sometimes it fixed itself after I had re-uploaded the SVG with non-essential changes; the other time it reverts to tofu glyph again. It doesn't matter whether we specify the exact typeface for the non Latin character or not.
SVG files observed with this glitch are File:Tokyu Railways topological diagram.svg and File:Min Kingdom, 945 v2 (zh-hans).svg.