I was having this problem with Maple Flow 2021, and just purchased Maple Flow 2022 but am still having this problem.
I define a variable, using := and an equation (that itself uses other variables that have been assigned a numeric value) and end it with an = and it is clear that the variable has a numeric value successfully assigned to it.
Lower down in the document, I use this variable, but it isn't recognized as having any numeric value or having been previously definied at all and when evaluated it stays in symbolic form.
I have tried deleting variables, renaming them without subscripts, retyping equations, etc. and nothing seems to work. Oddly most of the variables work, but some won't even though there doesn't seem to be anything special about them.
Any thoughts or advice would be greatly appreciated.