Unreliable - the classes aren't locked in until 24 hours before the class starts so you can't plan for your week or count on a set income.
Booking rate - they never actually explain how you can up your booking rate other than "take workshops" which are unpaid. Won't warn you that the booking rate might be low that month because of holidays or exams in China until it's too late to find other income.
Communication - you get spammed with weekly updates which are mostly other teachers posting videos on youtube. But when you email the teacher support you can wait days for a response.
Feedback - You have to leave individual feedback for every student after every class. You might teacher 4 or 5 classes back to back which means you have to spend time (where you aren't being paid) to leave feedback for upwards of 20 students. THEY FINE YOU IF YOU DON'T COMPLETE FEEDBACK. They didn't tell me I needed to do feedback after my first day at Magic Ears. I was fined $20 for unfinished feedback.
Feedback to teachers - Students can leave you feedback after every class. They don't have to write why they gave you 1 star they only have to click it. So if you have a misbehaved child they can just give you a low score for no reason. Teacher support will also only get in touch with you if you do something wrong or get low feedback scores for the parents. There is no praise and they don't recognize when or what you do well so the feedback to teachers feels very unbalanced.