Generator sometimes does not stop when reaching SOC stop condition

I have an off-grid domestic system using Victron Color Controller GX, Inverters and Battery Monitor. Recently, and intermittently, the Generator does not stop when reaching the SOC condition (90% charged). The Color Control screen shows ‘Generator Not Running’ but the auto-start does not switch off until I manually power down the whole system. I would like to seek technical advice on how to resolve this. The generator was unused for several months during summer while solar was high, so I suspected the power relay could be sticking, but changing the relay did not resolve the issue