Ah ah, yes tracing & debugging is what I've been doing and I'll keep doing.
It's just that after a while I also opted to share and increase the chances to reach a solution.
I've read this when Sebastian Riedel gave up with Mango develop
and I also know that Mongo no more officially supports Perl.
I had a chance to guess about the 'sharp tongue' reading both the discussion on issue 1223 and the following PR's review, but that is fine.

Yes, the versions of the old MongoDB cluster and the new Atlas one are different. It does seem, as you suggest, there is some incompatibility server side to also figure out.

Thanks for the advises and for your time.

In reply to Re^4: Mojolicious connection to Atlas ssl cluster fails: "Premature connection close" by jjmoka
in thread Mojolicious connection to Atlas ssl cluster fails: "Premature connection close" by jjmoka

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":



  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.