When repaying GUSD Borrow with WBTC or ETH, the slippage rate is nearly 13%.
This does not occur with DAI or USDC Borrow balances, however the extreme slippage occurs on every GUSD pair.
Per Discord support, it appears that it is utilizing a certain Uniswap pool for GUSD that is not optimal like Paraswap:
Example of the excessive slippage on AAVE:
Example of the swap on Paraswap:
Note: I was advised to recreate the swap using aTokens, and it appears to be the same, but the screen capture would not be accurate as prices for ETH have changed