I have to manage liquidity on a regular basis so that you get a fair price. If the price impact is high, there's a lack of liquidity (which can happen given the state of the market), if that happens:
1. Either redeem your WPIs directly on TokenSets instead of selling them on SmarDex: https://www.tokensets.com/#/v2/set/0xa6e265667e1e18c28F2B5dc529F775C5f0D56D4A
2. Or send me an e-mail to let me know and I'll add liquidity :)
Be careful, if you sell WPI at a crappy price because of Price Impact I can't do anything for you.