Is the continued receipt of salary from an organization in which work has ceased considered doubtful, especially since a portion of the organization's funds are charitable, and is it obligatory to leave work in this situation?

The ruling regarding your work in this institution depends on the administration's stance on the work stoppage and on the charitable nature of the institution's activity. If the administration strives to overcome obstacles and maintain the team to resume activity, then there is no blame on you concerning the salary, as this serves the institution's interest. However, if the administration is not keen on the work resuming, then their action is unlawful for violating trustworthiness. As for your salary in this case, if the institution's activity is generally charitable and you are in need of the salary, then there is no harm in taking it as a form of assistance for you. But if the activity is limited and you are not among the beneficiaries, then it is advisable to look for another job, and there is no harm in taking the salary temporarily until another job becomes available, while striving to occupy your work time with charitable deeds similar to the halted activity of the institution.