Miners are getting failed

[kevin1234a]

alright guys having trouble with the Gaw Furys, they were working fine till last month but now a days they kept getting failed to mine and switching to the alternate backup pools. is it because i kept directing them to the newly launched coins and difficulty level keep changing for those coins or the miners are DONE now?

my setup for this farm is:

10 GAW fury
RPi with minera
USB hub