This rounding down was made very clear in the BHP Merger Details...

This rounding down was made very clear in the BHP Merger Details released 8th April.

"The dividend is expected to be paid on 1 June 2022 to each BHP shareholder on the BHP
register2 at the close of business on 26 May 2022 (Record Date). BHP shareholders will be
entitled to a pro-rata share of the Woodside Shares received by BHP based on the number of
BHP shares they hold on the BHP register on the Record Date.
The current estimate of the dividend entitlement is that BHP shareholders will receive one
Woodside Share for every 5.5340 BHP shares. BHP shareholders will be entitled to a whole
number of Woodside Shares, with any entitlement to a fraction of a Woodside Share that would
have otherwise arisen being rounded down to the nearest whole number."

I decided to get a bit tricky when topping up my BHP holding so i was just over the fractions of shares.
ie. I had 1046 shares = 189.01 WDS shares.
Yes i was rounded down to 189 shares.