Does Google changing your meta-titles negatively impact SEO?

Recently my website was hit with a "penalty" of sorts, I believe and I have spent all of the latter part of last year, and the first half of this year trying to figure out what the issue is. I have noticed that Google has been selecting the meta titles for a lot of my pages as of the last year, and the way I used to formulate are no longer considered "good" (I guess?) by Google, and so it chooses the H1 as the page's meta title, or just selects its own for a lot of my pages

I was wondering, can this being the case on 80-85% of my pages negatively impact the SEO of my entire website overall? For example, even pages that this hasn't happened to have been negatively impacted in the rankings, and my startpage, which does have the meta-title I have set for it, has dropped to the second/third page, from being in the top 5 results on the first page

Can Google not liking the meta titles of a lot of the pages negatively impact the website's SEO? Instinctively, I don't think keeping my meta-titles like they are is good and I am going to change them, but at the same time, it wouldn't make sense that my entire website would be penalized in terms of SEO for something like this? Even pages that don't have this issue? Would really appreciate any help. Thank you so much in advance!

This happened to my site. I compared the page titles that modified by Google with those not modified. I think duplicate content or words may cause that google modifies the page title tag

Yeah it does. Duplicate occurrences of words cause it now. This didn't use to be the case. I've updated all mine now, will see if it'll change the SEO of the website overall