I am stressed out by the mysterious way that IRCC works. The tracker provides inaccurate information and the IRCC call centre also doesn't provide precise information on the application status.
My application status says that IRCC is waiting for additional documentation since September 22, 2022, but when I called them they said they don't require additional documentation. Communication is a serious problem, and waiting without an anticipated time is the hardest matter to deal with.
First, do not stress out... I know it is frustrating, but this is how IRCC functions and most probably there is nothing wrong with your application... you just have to be patient, and try to forget about it (I know easier said than done!).
Regarding your account showing waiting for additional documentation, and even though IRCC call center told you they don't require any additional documentation, I would re-check my email (including the spam folder) to see if you have received any email from IRCC requesting any documents. Also, make sure that IRCC has your current address, in case they mail you anything (there is a website to do so, but cannot remember it now). Finally, I would send a CSE via the IRCC Webform to inquire about the "waiting for additional documentation status" showing in your account since last Dec. All this is just because I do not trust the IRCC call center representatives, as they talk like robots, and most of the time don't share any useful info. Also, if you want, you can apply for GCMS notes, the myth says it will make an officer to check your file to prepare the notes.
Consider my suggestions above, then try to forget about your application, if you can. It will pass sooner or later, it is just a matter of time now. Good luck!
P.S. I received my oath invitation last week, I will do it on March 22. I applied in Dec 2021, and just did the test last Jan... I was very stressed out before, and was thinking if there is something wrong about my application, but here we are!