Is a man's work as a manager in a financial department that includes female employees in separate offices considered a sinful form of mixing (ikhtilat)?

Mixing (of genders) is of two types: permissible and impermissible. One can differentiate between them by reviewing fatwas number 49566 and 61890. If the mixing is governed by Shariah controls, then there is no harm; otherwise, one must be cautious to avoid falling into the forbidden. It is not permissible to continue in mixing that leads to temptation in religion and morals, except out of necessity or severe need, provided that this continues only until the necessity or need ceases, or Allah facilitates another permissible work. Please refer to fatwa (definition) number 104285.