I have read several times that in a BJT transistor the variation of VCE barely influences IC.
Looking at the curve graph of a BC550 I see that for an IB of 150 μA we get about 40 mA of IC regardless of whether VCE is 6 or 12 V.
I have assembled the circuit and I have verified that keeping IB constant at 150 μA and varying VCE between 6 and 12 V, IC varies between 30 and 64 mA.
Am I misinterpreting the graph of curves?
[Edit1] I have added the schematic of the circuit that I physically assembled, on the right is my Vc vs Ic measurement table
[Edit2] I have corrected in the table the value of 2v to the correct value 12ma, typing error