Link Load Balancing Persistence Problem

Hello everybody, l’m new in this forum. I use Fortinet products from a while and now I have to use a FortiADC 400D. I have a problem with the persistence in LLB. It doesn’t work. In the Link Group there are four gateways and the traffic is load balanced over them even if Persistence is configured. I didn’t find a CLI command showing the persistence table in LLB for troubleshooting. I can’t understand where I’m wrong. Thank you. GR