Does the Wash Sale Rule Apply Across Spouses and Multiple Brokerage Accounts?

Today, I sold 170 shares of QQQ at a loss to harvest tax losses, because I have a large capital gain from recently selling a rental property.

When I asked Google and ChatGPT, they said that QQQ bought within 30 days in other accounts—and even in my husband's account—would trigger a wash sale, so I would have to sell all those QQQ shares purchased within 30 days in other accounts as well.

However, a Fidelity employee told me that it doesn't matter if the accounts are different. Is the employee's advice correct?

Experts, please let me know!

Thank you.