In Lendgine the function collect is used by the users to collect the interest that has been gathered to their liquidity position.
The problem here occurring is that the function is supposed to accrue both the global interest and the users liquidity position interest to the current block.timestamp. Note that what l just described is true and its already applied in a similar function in LiquidityManager - collect(). Consider calling accruePositionInterest prior to executing the function collect, so the interest can accrued till the current time of the block.timestamp.
You can see that this is already applied in a similar function:
