Thanks for your response, I understand that it is a busy time.

Sorry that the in-line comments didn't detail all the device settings - I had attached a 12 page document ( "PIN_transientsim_explanation_of_results_and_setups_tested.docx") in the first post with all complete settings used, but I'll extract the screenshots and explanations of settings and tests to be part of of this actual comment as well. It's rather long, so I'll first answer your questions and then append it below a ------ demarcation line.
RE"Do you know what does the "transient" simulate?"-- first I just want the transient behavior of the current through the PIN diode in response to the applied voltage. In this case I do not have the optical/shutter on.

However, for the sake of being thorough, I have gone through, examined, and run all of the following transient explanations and examples below. They work as they should/advertised, but I am NOT interested in the transient results of the transient examples--- I only care about the PIN diode and it's transient response.

Thanks for your help, it is greatly appreciated.
Below, I will copy and paste the word document I had attached in it's entirety:

Begin document: ( EDIT: ok, I see that I am not allowed to put the entire document in, "Body is 7557 characters too long", I will break it in multiple comments then)

Issue: no reasonable current increase that tracks the voltage step in transient simulation for the default pin_mzm.ldev file from https://support.lumerical.com/hc/en-us/articles/360042327854-PIN-Mach-Zehnder-modulator

I will start with my last test result ÔÇ£..redo10ÔÇØ, that showed the same symptoms as others run before it.
Below is a view of the PIN MZM in Device/CHARGE, it is the pin_mzm.ldev, with simulation changed to ÔÇ£transientÔÇØ instead of ÔÇ£steady stateÔÇØ

I will start from the beginning:

I download pin_mzm.ldev, and change the ÔÇ£Edit Charge SolverÔÇØ menu to:

I make the input a voltage pulse, step up and down: