Hello guys!!! I recently found out about the skywater130 pdk and the open source analog design tools. So far I am having fun learning the tools and trying to design a simple op-amp. However I have come across an issue that I do not know how to overcome. Every time I try simulate the circuit with ngspice, I get a different operating point. This happens both with "op" analysis and "transient" analysis. In the picture below I present the transient solution of 3 simulations on the same spice file generated from xschem. I have highlighted with yellow color the output of the first stage. As you can see it is different every time. Has anyone had the same issue? Do you think it has something to do with the accuracy settings of ngspice? (I haven't tinkered with them) Thanks!!