Why is my wifi slow on a new update?

[AC Question]

Hello, I have a J5 and I downloaded new marshmallow update 6.0.1 and it felt normal, i connected to wifi and it was as fast as before... I started to download some programs and... the download speed was terrible, before the update i would download stuff 1mbps minimal, but after i download 400kbps is maximum... Anyone that can help about this ?

 

[belodion]

Was this an OTA firmware upgrade from Samsung?