So after being alerted by @tallship / @tallship & @silverpill that my ActivityPub settings were a bit wonky, I decided to take some time & investigate.
After further analysis, my settings were a bit wonky, as the site could no longer ping user handles (weird, I know).
I decided to embrace the spirit of Serenity / Firefly & quit “fiddling” to find out what the issue was.
So now, the site can ping users when mentioning handles, but I am still unsure why the site was not working previously or if the underlying issues were addressed.
If anyone else has any issues, feel free to ping me at @darnell (my Mastodon account), as being a part of the Fediverse is important to me.