Default Google Keyboard has about 200MB Traffic over night and maybe denies deep sleep

Hi guys,
with betterbatterystats i saw, that my google keyboard is causing about 200mb traffic over night.
Code:
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Network (requires root)
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10035 (Wifi) (com.android.inputmethod.latin.Google-Tastatur): 191.0 MBytes 92,1%
I guess this is the reason why my nexus 5 is on max cpu frequency for about an hour.
Why is it causing that much traffic?
And how can i prevent it from waking up my phone?

Do you see anything else which could cause my nexus to stay awake?

Thanks for your help!