What Sense version are you running? Do you get any messages in the scheduler logs? Could it be related to this issue Qlik Sense Scheduler stopped because of the corrupted performance counters?
We are running 11.24.1 of Sense server. I had my server admin investigate the link that you sent but he said that everything looked OK on that issue. He said that the logs showed the scheduling service crashing after startup (not sure of details). He is going to open a service request with support. Thanks for your help