Instrument Transposition Oddity

I am having an odd situation with instrument transposition. Maybe someone has some advice.
I'm working on a piece that calls for Clarinet in A. I set up my basic staff using score setup in Notion and identify that the staff is to transpose to A, same octave lower. The key signature adjusts itself at the beginning of the piece, and is correct for transposed view. All is good, life is smooth.
Then an odd thing happens. As soon as I call an instrument, it seems that the key signature for that staff reverts to something else. Why? If I try to transpose it to get the key signature correct then everything is off.
What am I doing wrong? Is it because I'm calling a Bb Clarinet as a substitute? Is there something in the VSL Bb Clarinet that changes the key signature in Notion?
I've been struggling with this for a while, any advice would be appreciated.
I'm working on a piece that calls for Clarinet in A. I set up my basic staff using score setup in Notion and identify that the staff is to transpose to A, same octave lower. The key signature adjusts itself at the beginning of the piece, and is correct for transposed view. All is good, life is smooth.
Then an odd thing happens. As soon as I call an instrument, it seems that the key signature for that staff reverts to something else. Why? If I try to transpose it to get the key signature correct then everything is off.
What am I doing wrong? Is it because I'm calling a Bb Clarinet as a substitute? Is there something in the VSL Bb Clarinet that changes the key signature in Notion?
I've been struggling with this for a while, any advice would be appreciated.