I need help getting IKea Tardiff On/Off switches to work with zha

Zigbee uses very low-power radios that are very susceptible to EMF/EMI/RMI interference and your description sounds like the typical symptoms of EMF/EMI/RMI interference. I highly recommend that you read and follow my collected tips here → Zigbee networks: how to guide for avoiding interference and optimize for getting better range + coverage (suggest beginning with connecting the Zigbee Coordinator adapter using long USB extension cable to a USB 2.0 port or via USB 2.0 hub in order to be able to move it away from all possible sources of EMF/EMI/RMI interference, and be especially sure that not connecting via a USB 3.x port or USB 3.x hub or even have it be close to any USB 3.x devices and cables to active USB 3.x devices)