it is a waiting game, you gotta let your accounts age for a while, while scrolling and lurking, reddit anti-spam system is extremely aggressive now, so if you post too soon you can get caught by the bot system. they can detect if you are using a VPN or proxy if they don't have stealth mode built-in.
use VPNs and Proxies that have stealth mode, they also flag you by your user agent, so if it is not matching to a real system, it gets flagged. configure your user agent properly to what is most common to blend in with the crowd.
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/79.0.3945.130 Safari/537.36
for example;
most reddit users are lurkers, so any new account with a lot of activity (posts/comments) are suspect and under scrutiny by the reddit anti-spam filters.
I am having difficulties as well getting a reddit account to work without the annoying shadowban triggers. ( I have no damn patience and also I have heard from legit users losing their accounts to shadowban just by using normally).
CQS score also weights in the shadowban, but as a new user there is not much you can do about it.
I am still experimenting with a lot of configs and methods, also if I have any erroneous info please correct me, as I like constructive feedback.