WiFi signal after android 7 upgrade

[Android Central Question]

I've just bought an Asus zenpad 3s 10 tablet. Upon setting up it upgraded to Android 7. I had trouble with signal strength in my bedroom (streaming movies) and agreed a return with the seller. However, after resetting the tablet I checked the signal again and found a full signal using android 6. Is there some tweaking that needs doing after firmware upgrade to get full signal strength with android 7 or should I just run the tablet with android 6. Thanks