Your order could be getting rejected because of the extra margin requirement.
Example:
Trigger price = ₹95
Limit price for SL order = ₹100
Groww Balance = ₹95
Now, apart from this, there are a few other charges that you have to pay upfront. Brokerage of ₹20 per order and other exchange related charges are required. This means, instead of ₹95, you actually require at least ₹120. This is the extra margin requirement in market orders.