A transaction can fail for several common reasons:
Slippage protection triggered - If the token price changed and the minimum output you specified was not met, the transaction automatically fails to protect you.
Insufficient gas - Your wallet may not have enough SHM to pay for network fees.
Price movement - If other trades occurred before your transaction was confirmed, the bonding curve price may have changed.
Network congestion - Transactions can occasionally fail if the network is busy.
When a transaction fails, your funds remain in your wallet. You only lose the gas fee required for processing the transaction attempt.
And, if a transaction remains pending for a long time, you can:
Wait for confirmation
Check the transaction status in a blockchain explorer
Cancel or replace the transaction from your wallet if supported
Sometimes a transaction may be approved in the wallet but not submitted to the network. This can occur if:
The transaction window was closed early
The wallet session expired
The network connection was interrupted
Try refreshing the page and submitting the transaction again.