BRepAlgoAPI_Fuse causes shape corruption

Hello. When I try to fuse shape1 and shape2, the result shape is corrupted. Is there something wrong with the input shape?

[Corrupted shape]

[Code]

BRepAlgoAPI_Fuse fuseShape( shape1, shape2 );
fuseShape.Build();
BRepAlgoAPI_Check analyzer;
analyzer.SetData( fuseShape.Shape() );
analyzer.Perform();
analyzer.isValid(); // <- Standard_False

[Envitonment]

Opencascade: V7.5.3
OS: Windows 10 Pro 64bit
CPU: Intel(R) Core(TM) i7-8550U
Memory: 16GB