Slippage not correlating with contract fees

Im running the dividend token smart contract and the slippage requirements for traders are much higher than the fees stated in the contract itself. It is not a matter of price impact/liquidity it seems either.

Also fair to mention this seems to only be happening on the Fantom Blockchain and has not been an issue on Polygon or Binance Smart Chain

A Link to the contract is here:

The current fees are total to 20, so a trader would expect to be able to submit a trade within the range of 20-22%, however cannot seem to successfully complete a swap until they reach a minimum of 27.5%