named parameter - sql assistant 15.00.00.03

If the “named parameter” you’re attempting to use starts with the letter “B” or “C” it doesn’t work.
 
Here’s a clearer example:
 
Prompts correctly for parameter:
select *
from DBC.ALL_RI_CHILDREN
where ChildDB = '?A'
 
Fails to prompt for parameter:

select *

from DBC.ALL_RI_CHILDREN

where ChildDB = '?B'
Also, further testing revealed that of the 26 English alphabetic characters, only B,C, & Y cause the problem.