Lost control of Leviton devices

[LAE]

Currently have an echo and two dots.  We have 10 Leviton DW3HL smart plugs and 11 Tuya smart plugs - all controlling various lights.  The Leviton have dimming capability and Tuya are simple relays.
Everything works on a common network and has been functioning well, until last night when Alexa could not turn off the Leviton devices.  The devices worked fine through the Leviton app.  When this happened before the problem corrected itself within an hour.  This time is different - through the echo, no connection to the Leviton devices for 16 hrs.

Any thoughts?

[renegade600]

I am not familiar with your devices so some of the following may not apply.  It is what I do when one of my smart devices decides to be stupid.  one thing, what does the echo do or say when you give it a command for one of those devices. 

1.  restart the phone
2.  open the Leviton app and see if there are any updates
3.  unplug your echo for about 5 minutes
4.  do a power cycle on your router.   unplug power for a slow 10 count
5.  unplug the smart device from the wall then plug back in after a few seconds.