How to Prohibit SharePoint Users From Sharing Site and Files

[Deleted]

I want to prohibit SharePoint users (members & visitors) from sharing the site as well as sharing individual files.  So I tweaked the SharePoint site settings as follows: Settings > Site Permissions > Access Requests Settings

I unchecked the box for: "SharePoint access request settings allow members to share the site and individual files" which also automatically on checks the box below it.

After successfully performing this task, I was surprised to know that users in the members permissions group can still share the site and individual files.  What action must I take as a site owner to prohibit sharing this site as well as individual files?

[#2]

@Deleted They shouldn't be able to share.

You've verified they're not in the owners group, right?

[#3]

Definitely not in the owners group yet can still share site, files, copy file link functionality, etc.

[#4]

@Deleted Hmmm. Consider raising a support ticket with Microsoft about this.

[#5]

No, they will be able to share always but only with users that are already accessing to the site what's fine: https://www.petri.com/disabling-document-sharing-users-no-access-spo-site

[#6]

@Juan Carlos González Martín - Even if I un-check the "Allow members to share the site and individual files and folders" at the site collection level? That is counter-intuitive to label on the checkbox. 

[#7]

@Juan Carlos González Martín  @Kevin Crossman  - To prevent file and site sharing as discussed, must this be done at the O365 level to disable SP sharing? I have done it at the site collection level via "Site Settings" but it does not impact members ability to still share. Thoughts?