Answer 1

Dronto
You can ask to sololearn by mailto: [e-mail] problem details with screen shot or video record will help more clearly to understand the problem easily. Devs can tell you whether is it device problem or any bug .. Is there any settings changes need, from their or your side? Devs can help you as much as they can and quickly.. But we are not.
So try to mail details. hope it helps...

Answer 2

<img id="robot" src="https://blob.sololearn.com/courses/robot-c.jpg">
<button onclick="robot.src='https://blob.sololearn.com/courses/robot-l.jpg'">Left</button>

Is this the code? It is working fine, in course, and in playground, you can recheck....

Answer 3

Clear the document and retype it, don't copy and paste. Sometimes when you copy and paste you also copy a over different (unicode) characters. That appear hidding in your document. Thus causing errors in your code.