Have a ton of Tp link switches. All have been working great with Alexa and the Kasa app for over a year.  This week, suddenly every HS100 stopped working.  All the other plugs are fine.  They don't even work in the Kasa App. Sometimes they will appear and say local only.  They do not stay online for more than a minute.  I removed them from my account.  Reset them and updated firmware. No luck. I now have 4 useless bricks. Any fixes?