Hamster's behavior changed rapidly! help

[Lefteris]

Hi my name is lefteris, im new to hamsters and i dont know a lot of things. First things first, i went to a pet shop and got 2 hamsters and i asked if it was okay to put them on the same cage something that i realized was a very bad mistake and something that a pet shoper would have to know... so after a few days the 2 hamster fought one another , and one died (ratatouille)
the one that survived (eggo) was having a good behavior he would eat from my hand and let me pet him, but suddenly he is a bit scared, i can put my hand inside the cage but he doesn't get food from it, or go near my hand at all.
eggo was not hurt from the fight at all
further more after the fight i cleaned the cage as much as i could and i gave him some days to get comfortable egain.
If anyone knows what could be happening or what can i do to tame eggo back i would be very happy to know.
(Both hamsters where roborovski)

[Petite]

It's great that Eggo would eat from your hand before this happened and allow petting, as it has taken me a long time just to get our Robo to take a sunflower seed from my fingers.
It could be that there was some kind of scent on your hands that made him a bit nervous. One thing you could try is washing your hands with unscented soap and then running them through the bedding before handling him, just so they are a bit more "hamster-friendly". Other than that, suddenly living on his own is a big change, so just allow him a bit more time to get used to the new set-up.Sorry to hear about Ratatouille. Unfortunately, as you have now found out, pet shop assistants often don't know nearly enough about the animals they are selling!

[Lefteris]

Thank you very much for you answer,
i always wash my hands before my hand enters the cage but i did not think that the scent from the soap would be a problem.
I will buy a unscented soap and ill late him adjust for a few more days.