Sometimes you seem very comfortable other than English language. Because everyone seems very comfortable in their mother language because communication and usage become very easy.
Because in many countries English language is not so popular so it’s a very good feature to understand Instagram App in their own language because in this way language barrier vanished.
This question is very important in this way that sometimes you accidently change your App language. So you can redirect it easily.
Open your Instagram account and go to settings like this
Now select language option like this
Now select any language according to your choice