After being demoted from a SSG to SGT, and then getting promoted back to SSG, do I have to redo all of my squad leader time?

If you made E5 from an E6 NCOER that said "squad leader" and "relief for cause", you're probably doing squad leader again.
If your squad leader time was done before this happened, then maybe not.

SGM (Join to see)
I was KD time Complete a year before this happened

SFC (Join to see) - To see if I understand, a scenario as an example: If a SSG gets a DUI and GOMOR, they face a QMP, correct? But, if the SSG gets demoted for the DUI, they get a pass from having to face a QMP? Am I understanding that correctly?

SFC Michael Hasbun no, he's going to have a negative NCOER in there that will probably delay his promotion for years. But he can stay to retire and he is safe from being kicked out by the QMP board

MSG (Join to see) no they still face the QMP if they get demoted. But if they get promoted that is the equivalent of the QMP board retaining the Soldier. One of the exceptions for QMP is if you have been promoted since the incident that refers you. So as long as you get promoted before the QMP board decides your fate, you are retained

SFC (Join to see) - Wow. Didn't know that particular part of QMP. Learn something new every day. Thank you for that education