Then it didn't work. You should have asked about it then.
There are 2 ways to shrink the array after making sure the disk is empty. The simplest is to New Config without the disk and rebuild parity. The other way is to clear the disk while it is in the array, then New Config without the disk and trust parity (since the clear disk has no effect on parity).
Either way New Config without the disk is necessary. You seem to have missed that somehow.
As far as Unraid is concerned, the disk is still part of the array whether or not it has any data, or whether or not it is missing or unassigned. In fact, Unraid has been emulating the missing disk all this time and you have been unprotected.