ofTrueTypeFont does not work properly on RaspberryPi3-Raspbian(stretch) with the drawString()

OF0.10.0-RC3, ofTrueTypeFont does not work properly on RaspberryPi3-Raspbian(stretch) with the drawString() method. Here are the codes:

//--------------------------------------------------------------
void ofApp::setup(){
ofTrueTypeFontSettings settings( "fz.ttf", 36);
settings.addRange(ofUnicode::CJKUnified);
settings.addRange(ofUnicode::Latin);
_font.load(settings);
}
//--------------------------------------------------------------
void ofApp::draw(){
ofSetColor(255,0,0);
char fpsStr[256];
sprintf(fpsStr, "framerate: %f", ofGetFrameRate());
_font.drawString(fpsStr, 100,100);
_font.drawString("你好,OF!", 100,400);
}

and the snapshot of the running OF window on Raspbian:
https://forum.openframeworks.cc/uploads/default/original/2X/8/8dec8b099302517837e930b00efb5010b3f5277e.jpeg

As you can see, the characters are improperly drawed as rectangle blocks. If I change the line

_font.drawString("你好,OF!", 100,400);

to

_font.getStringTexture("你好,OF!").draw(100,400);

The characters are correctly drawed, which is strange. But the code looks awkward.

================================================================
And I changed to use drawStringAsShapes(), the window will take about 10 seconds(tooooo long) to show up, but the Chinese characters could be displayed properly. Here are the codes:

//--------------------------------------------------------------
void ofApp::setup(){
ofTrueTypeFontSettings settings( "fz.ttf", 36);
settings.addRange(ofUnicode::CJKUnified);
settings.addRange(ofUnicode::Latin);
settings.contours=true;
_font.load(settings);
}
//--------------------------------------------------------------
void ofApp::draw(){
ofSetColor(255,0,0);
char fpsStr[256];
sprintf(fpsStr, "framerate: %f", ofGetFrameRate());
_font.drawStringAsShapes(fpsStr, 100,100);
_font.drawStringAsShapes("你好,OF!", 100,400);
}

and the snapshot of the running OF window on Raspbian:
https://forum.openframeworks.cc/uploads/default/original/2X/a/abcc55c44e561768169f5098d81aa6e81b792628.jpeg

Start by reproducing the provided ofTrueTypeFont setup and drawString calls on RaspberryPi3-Raspbian(stretch), comparing drawString with getStringTexture().draw() and drawStringAsShapes(). Done means Chinese characters render correctly through drawString without the workaround or the roughly 10-second startup delay.