I think this is definitely happening. I just got an email from rangers there stating i had left a ticket in my basket. Couldn't proceed with the purchase due to not having the T code.
You say later you don’t have the 105 requirement, That suggests you haven’t been allocated ticket(s). Did you get an email? If not it suggests you miss out.
I‘m now wondering though if the reason those who DO have the 105 code are getting no availability is because folk who do NOT have it are putting tickets in their basket only to find they can’t checkout.