Why does the transaction say 'TX Expired. Please Retry'?
You might be waiting too long before signing the transaction in your wallet. Generally, after the transaction has popped up, you need to sign it within 30-60 seconds. To reinitiate the transaction, you can close your wallet and click the “Sell xx Token” button again on the pocketchange.gg page.
Why does my transaction fail?
Transaction can fail for many reasons but usually on pocketchange.gg it is caused by sending the sell transaction multiple times. If the first sale already succeeds, the second transaction will fail.
In my wallet, the transaction already succeeds, but why does the token still show up at pocketchange.gg site?
Try to refresh the page, although it is rare, it might take some time before the change is reflected to the chain state.