There must be something wrong with your bank account, kindly confirm whether your bank account is working and can receive payments.
You can also reach out stake support through email regarding this , they respond within 12 hours.
On the sidenote, I have been using stake since 2 years and withdrawn numerous times that too thousands of rupees and never faced any issue, sometimes it took a couple of days to reflect in my bank account or my stake account but not more than that.