Cant understand the problem here!!

[TechnicallyKiller]

//FUNCTION CALL
function testEmitsEventOnEntrance() public {
// Arrange
vm.prank(PLAYER); // Set PLAYER as the sender of the transaction

// Act / Assert
// Expect the 'EnteredRaffle' event to be emitted with the PLAYER address as the indexed parameter
vm.expectEmit(true, true, false, false, address(raffle)); // Expect the event from the raffle contract
emit EnteredRaffle(PLAYER); // Emitting the event manually for comparison
raffle.enterRaffle{value: entranceFee}(); // Call the function to enter the raffle

}

//OUTPUT
Ran 1 test for test/unit/RaffleTest1.sol:RafflesTest
[FAIL: log != expected log] testEmitsEventOnEntrance() (gas: 68584)
Traces:
[68584] RafflesTest::testEmitsEventOnEntrance()
├─ [0] VM::prank(player: [0x44E97aF4418b7a17AABD8090bEA0A471a366305C])
│ └─ ← [Return]
├─ [0] VM::expectEmit(true, true, false, false, Raffle: [0xA8452Ec99ce0C64f20701dB7dD3abDb607c00496])
│ └─ ← [Return]
├─ emit EnteredRaffle(player: player: [0x44E97aF4418b7a17AABD8090bEA0A471a366305C])
├─ [47765] Raffle::enterRaffle{value: 10000000000000000}()
│ ├─ emit IndexedMembers(player: player: [0x44E97aF4418b7a17AABD8090bEA0A471a366305C])
│ └─ ← [Stop]
└─ ← [Revert] log != expected log

Suite result: FAILED. 0 passed; 1 failed; 0 skipped; finished in 9.15ms (681.80µs CPU time)

Ran 1 test suite in 15.07s (9.15ms CPU time): 0 tests passed, 1 failed, 0 skipped (1 total tests)

Failing tests:
Encountered 1 failing test in test/unit/RaffleTest1.sol:RafflesTest
[FAIL: log != expected log] testEmitsEventOnEntrance() (gas: 68584)

Encountered a total of 1 failing tests, 0 tests succeeded

[EngrPips]

The below is the stack trace of my test that passed, and the difference between my stack trace is that my Lottery.sol contract emitted the same event that I expected, but yours is emitting a different event from what you expected.

Traces:
  [68629] LotteryTest::testLotteryProperlyEmitEventWhenAPlayerEnters()
    ├─ [0] VM::expectEmit(true, false, false, false, Lottery: [0x9fE46736679d2D9a65F0992F2272dE9f3c7fa6e0])
    │   └─ ← [Return] 
    ├─ emit enteredLottery(player: player: [0x44E97aF4418b7a17AABD8090bEA0A471a366305C])
    ├─ [0] VM::prank(player: [0x44E97aF4418b7a17AABD8090bEA0A471a366305C])
    │   └─ ← [Return] 
    ├─ [47805] Lottery::enter{value: 10000000000000000}()
    │   ├─ emit enteredLottery(player: player: [0x44E97aF4418b7a17AABD8090bEA0A471a366305C])
    │   └─ ← [Stop] 
    └─ ← [Stop] 

[NikolayPIvanov]

Events in Solidity have signatures. The signature of an event is derived from its name and the types of its parameters. This signature allows events to be uniquely identified in the Ethereum Virtual Machine (EVM).

Looking at your code, the event used in Raffle.sol is IndexedMembers, whereas in the tests it is EnteredRaffle which is a different signatures just from the name.

Placing the same event name IndexedMembers makes the test pass.

Traces:
  [73092] RafflesTest::testEmitsEventOnEntrance()
    ├─ [0] VM::prank(player: [0x44E97aF4418b7a17AABD8090bEA0A471a366305C])
    │   └─ ← [Return] 
    ├─ [0] VM::recordLogs()
    │   └─ ← [Return] 
    ├─ [0] console::log("PLAYER Address: ", player: [0x44E97aF4418b7a17AABD8090bEA0A471a366305C]) [staticcall]
    │   └─ ← [Stop] 
    ├─ [0] console::log("Entrance Fee: ", 10000000000000000 [1e16]) [staticcall]
    │   └─ ← [Stop] 
    ├─ [0] VM::expectEmit(true, false, false, false, Raffle: [0x90193C961A926261B756D1E5bb255e67ff9498A1])
    │   └─ ← [Return] 
    ├─ emit IndexedMembers(player: player: [0x44E97aF4418b7a17AABD8090bEA0A471a366305C])
    ├─ [47765] Raffle::enterRaffle{value: 10000000000000000}()
    │   ├─ emit IndexedMembers(player: player: [0x44E97aF4418b7a17AABD8090bEA0A471a366305C])
    │   └─ ← [Stop] 
    └─ ← [Stop]

[EngrPips]

Great heads-up.

[TechnicallyKiller]

Thank you Sir!!