TLDR;
when I try to add an image, they don't show up in the "viewer" pane in Joplin windows (every version I've installed since late July), I just get the broken picture icon.
I have the files in directory, I click the paper clip in Joplin, browse to the image (.png file), select it, and it fails to load. This is how it shows in the markdown:

So, I checked, and it does add the file to the resources directory. (testing multiple times adds multiple copies to the resource folder, as expected, although it would be nice if it used a CRC hash or something to prevent duplicate items from being cached...)
I tried dragging and dropping the image from the resources folder into the note, and I get the same result, except it looks like this in the markdown:

and now I have a second copy of this image in my resources directory, but still cannot view it from the note.
So, now I tried copy/paste of the image, opened in a browser tab, right click copy, then ctrl+v in the Joplin note...

and I have 3 copies of the image in the resource folder now.
anyone can help?
This has happened on 4 different computers, probably 5+ different versions of Joplin as well, I'm sure I'm just doing it wrong, but have no idea what "it" is so I can fix it...
the long part
I have been waiting for a reasonable replacement for EverNote since their "You only get 2 devices unless you pay" business model came out and I quit using it. Simply because I have a phone, a laptop, and a desktop...
One day this past summer at work, I heard a vicious rumor that the company I work for was dropping Confluence, because of the way they store their data "could", "IF" a new vulnerability was found in AWS, allow a malicious person to gain access to the data simply by having access to another company's Confluence instance. This made me laugh until I realized I had spent the better part of the previous 18 months migrating all of my notes out of One Note and into a Confluence Space...
A co-worker of mine wrote some Python code to web scrape a Confluence Space out into word doc files because of this, pretty cool. I used that to get word files, then used a VB macro in Word to convert them all to DOCX files, so I could use PanDoc to convert them to MarkDown files, so I could import them into Joplin. No issues getting that all done, and besides having to clean up all of the pages manually (took me 3 months now, just finished tonight), It all came out good, except I cannot view any images in Joplin.