XLOOKUP error

[Harps79]

HI, I am finding that my XLOOKUP is not pulling the value I can see it should be pulling into my Data tab on my spreadsheet. I cannot see where I am going wrong! Can anyone help please? The formula I have is: 

=ROUND(XLOOKUP($A298,Allocations!$A:$A,Allocations!F:F,0,0)+
XLOOKUP($A298,Adjusts!$A:$A,Adjusts!C:C,0,0),0)

Its the bold part of the formula that is not giving me the values I am expecting. It just gives me a zero even though I can see it should be returning numbers like 100. 

[#2]

@Harps79 

How are you sure it shall return some not zero number? If in any cell

=A298=Allocation!<correct cell>

does it return TRUE of FALSE?

[#3]

Because I can see the values on the other tab that it should be returning. So for one the values it should be returning 100. Unless I am doing this completely wrong?

[#4]

@Harps79 

Values could look identical but being different, e.g. "abc" and "abc ". Or something with non-printable characters, especially if you copy/pasted something from the web.