I tried to answer a question and in the edit mode MathJax shows the equations properly, but when I click on "save" some equations are not rendered (?) at all, and I see only the MathJax code.
If I click on edit again, everything seems to be OK, but in normal viewing mode it is screwed up on my Brave or Edge browsers. I tried to edit again, start a new answer, etc., but I still had the same problem. What is wrong with my equations?