Multisite Upload path issues

I had more or less abandoned a subsite of ssnet.org (subdirectory-type install) after not being able to solve the problem of missing images a couple years ago after a major WordPress update. (WP 5.8?? or maybe it was a server update.)

My main site works fine with these settings:
upload_path /home/ssnet/public_html/wp-content/uploads
upload_url_path [blank]
fileupload_url https://ssnet.org/public_html/wp-content/uploads

I believe my upload paths for the sabbathissues.org subsite looked like this (lots of changing back and forth since then):
upload_path: https://ssnet.org/wp-content/blogs.dir/12/files
upload_url_path [blank]
fileupload_url https://sabbathissues.org/files

Upon moving to a new server, a tech support person went beyond the call of duty to apply a “band-aid” solution to make most of the images on the site show up. With a little sleuthing I found that he had inserted a directory redirect in the root directory (public_html). He redirected the address https://ssnet.org/files to https://ssnet.org/sabbathissues. And the images started showing up.

It so happens that I had reproduced the upload directory in the https://ssnet.org/sabbathissues as one of my desperate attempts to restore the images.

My current settings in the Networking Admin Sites setup look like this:
upload_path /home/ssnet/public_html/sabbathissues/files/
upload_url_path https://sabbathissues.org/files/
fileupload_url https://sabbathissues.org/files/

This works only after a fashion, because this is what happens:
When I upload an image it goes to
https://ssnet.org/wp-content/blogs.dir/12/files/2024/02 and the images do not show up in the Media Library unless I choose “Edit.” And they do not show up when I attempt to insert them into blog posts. I have to use FTP to move them to https://sabbathissues.org/files/2024/02, and then the images work as expected.

I tried removing the redirect, and the images immediately disappeared from the site. The only thing I did not try was to put the images in the directory that was redirected, namely https://ssnet.org/files. (Currently there is no such directory.)

I would like to get rid of the redirect, and I would like to be able to upload files and have them work without having to move them via FTP. (https://ssnet.org/sabbathissues is perfect as a file repository, as far as I’m concerned.) Perhaps there is something wrong in the Sites setup that you can see, but it doesn’t look to me like WordPress is paying much attention to the file paths.

(My previous post on this issue was Subsite images do not load after Update to WP5.8 or subsequent updates, but I believe my current questions are sufficiently different to warrant a different post, since I’ve done enough sleuthing to understand a little of what’s going on. Besides, the other post was kind of abandoned … )

I would really appreciate some help on this. (I also have another small subsite with a similar problem. I believe if we can get the one site to work correctly, I can make the other site work too.) Thanks in advance!

The page I need help with: [log in to see the link]