Small buttons inside d-flex no longer small

[Adria-indico]

Prerequisites

• I have searched for duplicate or closed issues
• I have validated any HTML to avoid common problems
• I have read the contributing guidelines

Describe the issue

After updating to 5.3.0, buttons with class btn-sm are no longer small if inside a d-flex (or d-sm-flex).

The issue was marked as fixed in 2021: #34834

Reduced test cases

What operating system(s) are you seeing the problem on?

macOS

What browser(s) are you seeing the problem on?

Chrome, Safari, Firefox

What version of Bootstrap are you using?

v5.3.0

[github-actions]

Hello @Adria-indico. Bug reports must include a live demo of the issue. Per our contributing guidelines, please create a reduced test case on CodePen or StackBlitz and report back with your link, Bootstrap version, and specific browser and Operating System details.

[github-actions]

As the issue was labeled with awaiting-reply, but there has been no response in 14 days, this issue will be closed. If you have any questions, you can comment/reply.