I am a current registered manager of a vulnerable adult care

Thanks for your patience. Whilst this may be a new services your employment rights should not be affected and the employer cannot just consider dismissal for example. This is an historic criminal record, it is also something which the employer was aware of all this time and it is not a surprise that you had this. You have not acted in a manner which would amount to misconduct either, such as trying to hide that from them.
The record is not for an offence involving children and as such it should not affect your ability to perform that job. Thai may have made you unsuitable for such a position but on the facts it does not affect the performance of that job and also there are no other reasons to doubt your qualities as you have been with them for a number of years with no issues and they know that you are a reliable employee
So it is best to wait and see what they say but I would hope they come back clearing the way for you to start working in this position.
I hope this has answered your query. Please take a second to leave a positive rating, or if you need me to clarify anything before you go - please get back to me and I will assist further as best as I can. Thank you