I have a feature class that was added to an EGDB after the database was registered as a data store in Server Manager. I would like to publish the new feature class to our Portal. There were no issues doing this with feature classes that existed before the database was registered. How do I register the new feature class with the existing data store? I don't want to use the option to register from the Analysis tab in Pro, because it creates a new Data Store entry. If layers are added in the future, this could create a lot of Data Store entries and I am trying to avoid that. Running as a test environment using ArcGIS Enterprise 11.3 on a single SQL Server 2022 deployment. I am sa on the SQL server and admin on the EGDB.
The registration is for the database itself and it should include everything in this database old or new.
Most likely you used a connection that is a little different then the one that is registered.
I usually create a temporary registration from Analysis tab, then I compare it with the existing one.
After I find the difference I drop the layer and the temporary registration and get the layer again using the correct connection and republish.
Have fun
I think you and @RyanUthoff both answered my question. I remembered it being easier when I did the original EGDB registration and that adding feature classes and tables didn't affect the registration when sharing. I believe the reason it isn't working in this case is because the database was set to Traditional Versioning by default when I registered it and we use Branch Versioning. When I versioned one of my datasets, that caught my attention. I didn't realize that the version style could affect the registration of my database, but it makes the most sense. If that isn't the answer, I'll edit this response. Thank you!
ModyBuchbinder already answered your question, but I have a couple more things to add to it.
You didn't directly call this out, but just wanted to say that if you already have an EGDB and then create a new table outside of Esri (like directly through SQL), then you will need to register that individual table with the DB (register with geodatabase tool). But, you do not need to re-register that DB connection with ArcGIS Enterprise. As ModyBuchbinder said, once you register the DB connection, all future tables will be included.
One other thing to note, which has got me a couple times, is that you are registering a specific version of the DB with the server. I've unknowingly been in another version of the EGDB that hasn't been registered with the server, and it asked me to register it when publishing. It wasn't until then I realized I was in a different version (of course this only applies if your data is versioned).