Shaders are compiling with DirectX 11 even when disabled?

[olive dock]

I made a compute shader and I got following message which seems to be related to DX 11 only, I tried to disable it keeping only DX 12 for Windows but I still get the error and shader won't run, any ideas why this happens? Obviously I could just fix the issue by putting there the literal but I don't want to support DX 11 anyway.
Shader error in 'Shader': 'chunkLength': initial value must be a literal expression at kernel CSMain at Assets/Code/Shaders/Global/Global.hlsl(5) (on d3d11)

[elder cedar]

Maybe share the code as well. At leadt the line in question with some context.