Thats why I suggest stressing they have to be absolutely committed to learning english and taking every opportunity going to learn it.
If you have guests who decide to hide in their rooms, you have little option but to give them a gentle kick on this, even if they are depressed / traumatised, because unfortunately unless they do even simple things like watch tv, talk to hosts or try to interact with others outside the house they are wasting their own time and the hosts efforts and its going to make things more difficult and stressful in the long run.
Its a very hard thing to tackle, but it does need to be addressed head on from the word go in my opinion. Even if you don't want to be here, you have to take it as an opportunity that you have to put heart and soul in. Anything less and you are not going to make it work unfortunately because thats the cold hard reality of being a refugee where you just have to get on with things and almost throw yourself in the deep end, out of your comfort zone much more than you perhaps are used to.
Knowing and accepting that for some time you are probably not going to be able to do a lot of the things you want, is part of it. You have to have a longer term goal - even if that is going back to Ukraine eventually - but the mentality has to be to go back having done something here even if that is purely to learn english and make friends.
It sounds awful to be so blunt about it. But I do think its the major difference between making it work for you and not work - especially living with hosts.
I am seeing which hosting arrangements are working and which are not. The ones that are breaking down are often down to finances of the hosts or guests not grasping they have to put in effort too.