Submitted by 0xpiken, also found by Afriauditor (1, 2), Agontuk, VAD37, monrel, and Trooper
https://github.com/code-423n4/2024-07-loopfi/blob/main/src/PoolV3.sol#L549 
https://github.com/code-423n4/2024-07-loopfi/blob/main/src/PoolV3.sol#L553
Either the profit or the loss is calculated incorrectly, resulting in the treasury owns incorrect profit balance.
Anyone can deposit WETH for lpETH by calling PoolV3#deposit() or PoolV3#mint().  The exchange rate of WETH:lpETH is 1:1.
The eligible credit manager can borrow WETH by calling PoolV3#lendCreditAccount(), and repay the debt and profit lately by calling PoolV3#repayCreditAccount().
The corresponding amount of lpETH will be minted to treasury if there is profit, and the corresponding amount of lpETH should be burned from treasury if there is any loss:
However, convertToShares() is used to calculate shares for profit and loss, while  _convertToShares() is used to calculate shares in PoolV3#deposit().
convertToShares() uses the exchange rate of E4626 to calculate shares instead of 1:1 exchange rate defined in PoolV3.
The incorrect convertToShares() call could highly return less shares than expected, resulting in the treasury owning incorrect balance.
Use _convertToShares() for share calculation:
Math
0xtj24 (LoopFi) confirmed
