S-1 continues to slip while playing sports post-fusion

I had a spinal fusion December 2011 at UCSF with the top surgeon, Mummaneni for L5-S1 for the condition Spondylolisthesis.
In the 15 years since then, the S1 continues to slip while engaged in tennis or pickle play. This occurred in 2021, which prior to a SCS, I had epidurals to L3, prohibiting relief, due to the scoliosis, providing no relief.
SCS was removed March 2025, where the S1 hs slipped three times in the past 12 months. I am due for an ablation, awaiting to speak to a pain management doctor, ye the surgeon I spoke with recently, mentioned a relatively easy procedure to a Sacroiliac joint fusion is a minimally invasive procedure.
Has anyone had this procedure/s surgery?