Here is a native that wants to help you 
It is mostly used when one thing is happening after another. However in this case you also use "and " in English, not always "then"
e.g.: Kahvaltı yapıp evden çıktım. I had breakfast and left home. OR I had breakfast and then left home . (even if you don´t use"then", you know breakfast was the first action)
You can also understand that two things are not happening at the same time if you swtich the position of "-ip"
i.e.: Evden çıkıp kahvaltı yaptım. I left home and (then) had breakfast. (obviously I did not have my breakfast at home)
The thing confusing you is that we also sometimes use it for spontaneous actions!
Although "-erek, -arak" is more suitable in this situation, "-ip" is also used!
e.g.: Mısır yiyip film seyrettik. We watched a movie while eating popcorn./We watched a movie and ate popcorn.
OR
Mısır yiyerek film seyrettik.
I wonder if the information above only depends on you having been speaking the language as a native for 23 years, or it is from books used in general education curriculum, reliable sources, linguistic articles and so? Can you cite some sources supporting your point?
sure of this
