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human
[MCU] Correct me if I wrong but they cannot return the stones back once they have taken them right? re:MCU time travel rules

I thought I got this but I don't think I quite agree/understand the whole thing so please correct me if I am wrong (which I probably am) 

The golden rule of MCU time travel is essentially "you past is the past, once you travel back in time, you are creating a branched timeline where your actions has changed it future"

So given this logic, once they have taken the stones they have created a different timeline where events are happening differently in the prime MCU timeline (re: Loki TV series). But when they return these stones, wouldn't they also create another new timeline since they are making another change in the past? i.e. by returning the stone, there would now be another timeline where the stones are *not* returned. since every time you go back to the past and did *something or anything* you are making alternate realities. 

my logic can be wrong but unless traveling to the future of the alternative timeline (relative to when they have taken the stones) is **not** included in the rule stated above I don't see how they will not generate a new timeline in which the stones are not returned. 

Sorry for the long read.
gpt
With the power of Pym they can basically get right back to the 'same' alternative timelines that they took them from and in the same instant they left, so for the purposes of that time stream the stone never left.  

So when hulk gets the time stone, for example, he walks over away from the Ancient one and vanishes and Captain America appears in the same spot and hands her the stone back.  She probably watched the whole thing and the stone was only out of her hands for 30 seconds or so.