ADP1031-2 working in PSM mode

In our product ADP1031 sometimes switches to Power Saving Mode PSM (with skipping pulses). In this case, everything works, but there is an interference at a frequency of ~7 kHz (Fsync = 512kHz/72), which falls into the band of the measuring chain of the product. This interference degrades the parameters of our device to unacceptable levels. How can we avoid the swithing ADP1031 to PSM mode?

Best Regards,