Input impedances in CB and CE transistor circuits
ehm... Proteus forgot to tell you your Transistor is blown with Vbe-5V but it did try to limit the current by some bulk resistance for Vbe and Vce.
Both of these circuits are neither CB, common base nor CE, common emitter.
WHY? because you have no current limiting resistors and logically the ground symbol is just an arbitrary convenient way to define 0 Vdc and not &quot;earth gnd&quot;. But Proteus may have assumed the bulk resistance for saturation of Vbe and Vce for your device and displayed that current. (IDK) I don't know... It's a Proteus error exceeding device Vbe ratings by orders of magnitude.
You could have in fact chosen any terminal as 0V but that does not make it CB, CE or CC, until you add resistors to modulate the voltage or current to achieve some voltage and/or current gain with a common terminal, shared between input and output.
The gnd. symbol only means an arbitrary 0V Reference.
Here is Falstad's simulation of the Shockley Equation and it will blow up with GigaAmps because it is not device-specific, so I added the necessary resistors to conform to the model for CB and CC.
You simply choose hFE but in more advanced details you may choose a dozen unique device parameters for diodes but these are not needed if you add the bulk resistance e.g. Rce=Vce(sat)/Ic(sat), but as a current sink/source ,this is never needed.
I spent a few minutes adding some sliders for the ideal voltage sources and added resistors. The voltage varies from a range of Vbe 0.6V to your 5V.