Not necessarily. Ideally, it should be similar, but the salary, both as an employee and as a member of the board, may vary each month. That is, you do not need to always assign the same salary.
We recommend you write an employment contract for yourself in which you specify a base salary and a variable productivity bonus. For example, imagine that some months you can only pay yourself 1000€, but others you have enough income, which allows you to allocate up to € 500 salary.
In that case, you could specify a base salary of 1000€ per month, plus a variable productivity bonus of € 500.