When your Swap order amount is very close to the maximum and minimum allowable limits, market movements may cause your order value to increase or decrease beyond those limits.
As a result, your order will fail.
Cryptocurrency markets can be volatile which means that fluctuations in asset values are inevitable. These fluctuations can increase or decrease the value of a crypto asset.
In these cases, the best option is to re-submit your order with the desired amount in fiat currency.