Greetings,
That is a noteworthy observation, I consider this to be a bug.
For what it is worth, to get the program to behave correctly, you can:
- evaluate upon assignment (See variable 'D' below)
- utilize evaluation upon assignment: eval() (See variable 'F' below)
- nest two functions: mat2sys(vectorize()) (See variable 'G' below)

May this be of Good Help;
⚜ Kenny Lemens, P.E. ᵂᴵ
"No matter where you go, there you are." -Buckaroo BanzaiHotkeys: https://en.smath.com/forum/resource.ashx?a=45771&b=2