Mac mail attachments are open in background not in foreground

I have experienced after Big Sur installation that any Mac mail attachments are open in the background instead in the foreground like in the previous Mac OS versions. It is not comfortable as I never know after double click on the attachment whether the attachement has been already opened (so opening it several times) and I have to always take one more action - either click on the relevant app or check all opened windows in the background. Have you experienced the same probem? Is there a way to change it in the setting? Thank you.