how is your signal? Maybe thats y.

Any buy from g store? legit ori set? it say 625 then say decacore.....

I meant the strength, go inside battery settings there, if it's bright green then good signal, if lots of yellow then bad signal. But if keep changing between 3g/4g maybe you can try set it 3g only and see if improve?

Basically 16nm=14nm, 16nm maybe even better few years ago(search iphone 6 tsmc vs samsung), just different company. For battery life lower nm is better. Then also must see type of core, big core(a75/73/72) are more powerful performance wise but use more energy.

So like this phone you can see, the mediatek version has big cores but on older process, that's why they have good benchmarks but bad battery life. SD version has no big cores and newer process so worse performance but very good battery life. And the thing you need to keep in mind is also that when phones heat up, they don't have fan to cool down, they drop their clockspeed instead whereas chips on newer process can run at higher clockspeeds for longer cause it takes longer for it to heat up. Thats why many feedback sd version redmi note 4 better.

To simplify, right now the power/performance these chips can consider same range. Of course radio signal strength I cannot say cause i never use all the different product before.

sd625, kirin65x, mediatek p series, Exynos 7870 Octa

sd660, kirin 960

sd835, exynos 8895, x30(maybe lower performance cause only 2 big core), kirin970

Sounds like either issue on google services or it rebuild database or something like that.