Phantom's automatic slippage setting can be high on a volatile or thinly traded token pair. Its current guide says the wallet aims for the lowest tolerance likely to make the swap succeed.
That tolerance is how far the execution price may move from your quote. Leaving it on automatic lets Phantom choose that allowance for the trade, rather than applying a fixed percentage you've selected yourself.
Before confirming, open the swap settings and check Slippage. You can set your own value between 0.1% and 30%. A lower limit can mean the swap fails if the price moves beyond it; a higher one allows execution at a worse price.
Source: https://help.phantom.com/articles/adjust-swap-settings-in-phantom-27085326202515
That tolerance is how far the execution price may move from your quote. Leaving it on automatic lets Phantom choose that allowance for the trade, rather than applying a fixed percentage you've selected yourself.
Before confirming, open the swap settings and check Slippage. You can set your own value between 0.1% and 30%. A lower limit can mean the swap fails if the price moves beyond it; a higher one allows execution at a worse price.
Source: https://help.phantom.com/articles/adjust-swap-settings-in-phantom-27085326202515