The most common and most likely answer to this crossword clue is the 9 letter word NORMALITY
I've seen this crossword clue in Financial Times
N
O
R
M
A
L
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T
Y
Buddy explains!

The straight part
We know that "business as usual" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case business as usual = normality.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does NORMALITY mean?
NORMALITY noun- The state of being normal or usual; normalcy.
- The concentration of a solution expressed in gram equivalent weights of solute per litre of solution.
- A measure of how well an observed distribution approximates a normal distribution.