Oh, I forgot to mention:
Yes, my clients are all pointing to the /nextcloud directory. They actually have to in order to be able to authenticate with the server and sync. The server URL is required upon sign-in. As I have shown above (and copying here), the clients are making requests to the /nextcloud directory:
e.g.
2023-03-02 16:22:12:422 [ info nextcloud.sync.networkjob.jsonapi C:\Users\sysadmin\AppData\Local\Temp\2\windows-13476\client-building\desktop\src\libsync\networkjobs.cpp:829 ]: JsonApiJob of QUrl("https://xxx.xxx.xxx/nextcloud/ocs/v1.php/cloud/user?format=json") FINISHED WITH STATUS "OK"
However, I am still gettting 403s. I do not see any requests from my Windows client to the base directory (/var/www) in the logs. So, I am stumped.