Hi Abhay,
Look over your screenshot, you are using masking rule for MBS so your main bank GL must be with the same logic number.
see your check payment masking logic is ++++++++11 and you are using GL 12150611 so your main bank GL should be same number upto 7 digits and end with zero and that would be 12150610,
In this way we inform the system to pick correct GL and clear the open items of bank sub GL.
Create GL 12150610 in your test system and try once.
Regards,
Mohammed