This has certainly been discussed multiple times before, here are some discussions I remember:
The important thing to know about the Pinyin on LingQ is that it is auto-generated by a software running on the server. This means, you cannot edit or correct it and it is unrelated to a specific lesson.
As you have noticed, the software has a tendency to select the most obscure reading of a word. But in the case of 着 it is impossible to guess the reading without context. I would recommend you rely on native audio to learn the correct pronunciation whenever possible, all lessons in the library should come with it. Text-to-speech software can be wrong as well.
The only way to assure that you always have the correct Pinyin is to copy it from a dictionary when you create a definition. If your dictionary language is English you should see that many, if not most, definitions already contain the Pinyin.