Default [Q] Suspect in Rooting LG L70-D325

i have lg l70 d325
i rooted it a few days ago.
today i got 158MB Official LG Software update.

i download it and click on install.

but shows me this error:
This device suspected in rooting.

i decided to unroot the device.
i unrooted the device and do the Hard Reset too.

but when i download the software update and install it again, it shows me that error.

i checked my device with the root checker its UNrooted but always LG Give me that error:
This device suspected in rooting!!!

its weird !!

Please Help Me.

Sorry for my Bad English.