RL transient circuit symbolic bug.
First answer only correct with old symbolic engine.
Second answer only correct with new symbolic engine.
Did you report all your findings concerning "friCAS vs muPad" to PTC support?
They should be interested in those bugs and disabilities as their goal should be making "their" symbolic engine performing better.
Or maybe they intend to replace muPad by friCAS just because they want to avoid having to transfer royalties to Mathworks in the future?
Send your issue by using the "Case Logger" tool, here: https://support.ptc.com/apps/case_logger_viewer/auth/ssl/log