Hello@OwenS ,
'Cloud send cmd failed' Error could be related to some settings on router/ modem, please refer to guide here to troubleshoot:
Why can’t I enable Remote Control on the Kasa app?
https://www.tp-link.com/support/faq/2243/
If the concern persists, can you help confirm some details here:
Model of the router and ISP:
MAC address and S/N on the label at bottom of the smart device & MAC address on the device label (you may create upload the photos to google drive and share via private message) May I know has Kasa device worked fine before?