How to avoid page break between subsection and subsubsection

In this specific page, the subsection and subsubsection are being separated, and there is enough space after de subsection:

However, on other parts of the document it works correctly:

I tried using nobreak, minipage. Didn’t work. The code in the breaking point is as it follows:

Don’t know if it has anything to do with it, but the error message is "Missing $ inserted".
Does anyone have a solution?
Thanks!