The 1632verse is a BIG place. Dozens of novels. Over 100 magazines issues. 200 authors (more or less). Millions and millions of words. And not ret-conning. Keeping it all consistent is not easy and it most definitely isn’t accidental. It takes a lot of work and a lot of cooperation. It also takes rules and a willingness to follow them.
Some of the most critical tools for ensuring this are the Grid, the Story Timelines and Story the Time Frames.
If you are just getting started, Eric Flint’s 2020 Recommended Reading Order for the books may help you.