I know nothing about how all this works once the SS get involved but it sounds like they suspect your daughter is drinking and don't want to make the mistake of putting your DGS back with her without being sure so I guess that might be a good thing. I realise your DGS is ASD and that makes it so very difficult for him but imagine him being sent back to his Mum and the chaos which would inevitably be part and parcel of his life before it disintegrated completely. Of course this doesn't take away the upset for you and DGS but the end result could be more positive with the threat of him going back to his Mum completely removed which sounds as if he finds it too overwhelming. At least at a centre it is not your word against your daughters and I suspect that if she if drinking again, it will quickly become obvious because it is an extremely slippery slope for an alcoholic.
It may be they are looking at your role to ensure that you are protected in the case of ill-health and that your daughter will not be able to just step in if you were hospitalised suddenly, which could happen to anyone.
You have done such a fantastic job so far and I am sure that they will let you continue because, with all the best will in the world, it would not be easy to place your GS anywhere else. Hopefully this is a blip in the process which will see you and your DGS return to a more settled future.
Good Morning Thursday 14th May 2026
When Is News Not Really 'News'?
When a political leader lies on their CV - can you trust them?
from me.

lol