Should someone continue with their PhD if they fail the core courses in master's? A friend of mine had failed core courses during his master's program. He had to retake the exams and passed them with minimum grade. However, his research output was good and he was able to publish a journal paper (first author, IF~4).
Now he has been accepted for a PhD in Canada on the same topic as his master's. He will be working with application of the courses he had failed in.
Should he continue with his PhD journey? At the university he will be carrying out his research, they don't have to take any coursework. So, he would have to continue with his research without having to take any courses.
Is he suitable for PhD? As far I know, PhD students are supposed to be proficient in the coursework.
I'm going to answer here as if you are the &quot;friend.&quot;
If the university accepts you into a doctoral program they have fairly high confidence that you will be successful. Otherwise they are just wasting scarce resources, including money, space, and faculty time.
It may be that you have some deficiencies and I hope that the educational system in place gives you the time and opportunity to fill any gaps, but you probably also have some compensating points in your favor.
It is good, of course, to try to figure out why you had issues in the past and to correct what can be changed.
But doctoral work is different from coursework and the skills required are not the same. Trust the people who admitted you to the program that you can do it.