How to add numbers instead of concatenating them?

How to add numbers instead of concatenating them?

Hello,

I am having a very strange issue where two Decimal Numbers are being concatenated instead of added together.

In my query I do the following:

SELECT
  "A",
  "B",
  "A"+"B"
FROM Table

An example result that I get is:
A
B
A+B
2
5
25

The expected result for A+B should be 7, not 25. It seems that the SQL is treating the columns A and B as strings instead of numbers.

I've tried wrapping them in the to_decimal(), or cast(), and they have the same result.

Does anyone have any ideas?