Hello @ams2022 

Thank you for reaching out to us, may I know how about the led status on kasa device when issue occurs, is it flashing green or red? 

For the kasa device unstable issue, you could try some suggestion here: 
1. Make sure the kasa device is receiving good Wi-Fi signal:
Kasa app-> Device Settings-> tap router Wi-Fi symbol->  signal strength (value of the dBm)
(40dBm- 70dBm is good to average, less than -70dBm is relatively poor : relocate smart devices or router closer to each other)
2. Please confirm kasa device firmware and kasa APP version are up-to-date 
3. Ensure smart device is connected to main router directly, not through AP or extenders
4. You could try to change a different 2.4Ghz Wi-Fi channel on router and see if that helps 
5. Turn off Advanced wireless settings like Wi-Fi Optimizing (Channel Optimizing)/ Band steering( Smart Connect )/ Mesh feature etc

If the concern persist, can you help confirm some information to locate the issue: 
1. The Router model:  
Does smart device connect to router directly or through extender nodes in a mesh system? 
2. How about the LED on smart device when issue occurs,
The  frequency of the issue:
3. Can you control the kasa device locally (when phone connected to home Wi-Fi) when the issue happens? 
4. MAC address of the kasa device (please share via private message)

Thank you.