Submitted by kodyvim, also found by minhtrng, QiuhaoLi, ast3ros, bin2chen, 0xnev, nobody2018, jasonxiale, Kow, ayden, chaduke, and SpicyMeatball
Function _hasFallbackToggled would be set to false on createMultipleSettlement regardless of user intentions.
Users can specify if they want a fallback on their transaction, which prevents the transaction from reverting in case of failure. But due to an incorrect flag, this would always be set to false.
https://github.com/code-423n4/2023-09-maia/blob/main/src/RootBridgeAgent.sol#L1090
The variable _hasFallbackToggled can be set to true or false depending whether the user wants a fallback or not.
If true, the value at the payload index 0 (payload [0]) would be set to bytes1(0x02) & 0x0F but this would still results to bytes1(0x02); otherwise, false this would also results to bytes1(0x02).
On the destination chain, to check for the fallback status of a transaction: 
https://github.com/code-423n4/2023-09-maia/blob/main/src/BranchBridgeAgent.sol#L651
_payload[0] == 0x82 would always be false; irrespective of the fallback status chosen by the user.
A simple test with chisel:
This would result to unexpected behaviors and issues with integrations.
Change the following line to:
Error
0xLightt (Maia) confirmed
0xBugsy (Maia) commented:
