The audience does not see my posts.

Yes, but that's not the problem: my profile appears in the search engines but it doesn't contain my public posts.

If public posts couldn't appear, why would Facebook specify "anyone on or off Facebook"?

It's already done.

(The screenshot was just an example to show that the "public" status also pertains to "off" Facebook individuals, and not just users as you mentioned).

Any other ideas?...

Yes.

The recovery time in engines is not immediate by any means, even for FB. The algorithms of the engines are complex, don't index all of FB in the same way and moreover, for Google, they have just changed again.

Furthermore, FB's "precepts" are not reliable; they change them regularly too, and the number of instructions or information concerning FB that are outdated is counted by the hundreds.

Thank you, but as I said, it's not a search engine issue since my profile appears without any problem.

The problem is that my posts show up for my friends but not for the public, even though they are set to "public."

So it’s to FB that the question should be asked, or even to Google. I said that SEO is complicated.
You’re talking to me about FB visibility (your friends) and visibility on Google (or elsewhere), and there is no connection between the two.

No, you didn't understand anything: I never talked about visibility or Google.

I'm just talking about my posts that are only visible to my friends instead of being visible to everyone (even though I've set the audience to "public").

"Yes, but that's not the problem: my profile appears in the search engines but it doesn't contain my public posts."

You have to know...

Thank you Gugu01 for your response :-)

Yes, I did all that: when I preview "as Public," I can see my posts, but when someone visits my profile without being logged into FB, they can find my profile but do not see my posts (yet FB clearly specifies that "Public" allows access even to those who are not logged in: see the link in my 2nd post).

I'll send you my page in a private message.

So, on your profile as:
_ public not connected to FB, I see nothing.

_ connected public, I see different photos, the most recent one is "Surdo'Rei at the Granville Carnival 2018"

Personally, I have a public post, and it shows:
_ public not connected to FB, I only see the photo that corresponds to my post.

_ connected public, I see (no other account to test lol) but no worries, the public sees the entire post.

Simple observation:
I tested with about ten random people.

We see that without being connected, only certain photos appear, the "about..." section, the Favorites, ... (depending on permissions)
But it’s true that no post ever appears.
(And with each click tested, there is a request to connect)

Either they have all hidden their posts and I was just unlucky, or it's not possible.

Do the test.

Finally a clear and precise answer, thank you for your research (which corroborates mine):
The problem comes from what FB calls "public" and its inconsistency between what it displays (access to "anyone on or off Facebook") and what it actually allows (limited access).
Thank you Gugu01 and have a good day!

You're welcome ;-)

"Finally a clear and precise answer" the people are volunteers and help based on what they understand of the problem, and it's not always easy to understand each other.