2. Perhaps the first thing that catches your eye is that there are many expressions of words earlier, and you are exposed to more words and expressions, so your Chinese is better than math.

It is also possible that some chains were broken when you were studying math. If some knowledge is not understood, it will transition to new knowledge. Mathematics is a discipline with a close knowledge chain. Once it is broken, it is difficult to learn. You can find out the reason and make up the knowledge of broken links. I think it would be better then.