Your rankings tanking on/around 10/19's update looks like a strong correlation. Your GSC with congruent drops in impressions and clicks doesn't immediately look like KWs you were top 3 for suddenly dropping further down the page-- else impressions would be similar but AP/CTR would just be tanking.

If you're using GA and your traffic doesn't have tons of seasonality, look at the landing page report month over month and see which pages have had the largest drop (can also do this in GSC). Then check in GSC and see what those pages' APs have done over the same period.

What types of links is GSC showing? Google says they don't count bad links, but if they make up a large proportion of your site's backlinks, SpamBrain (their spam AI-- publicly announced more frequently) may bucket your site that way.

SEMrush, ahrefs, Majestic, Moz OSE are all decent for checking who is linking (and maybe disavowing), but LinkResearchTools is probably going to focus more on identifying suspicious backlinks, if that is in fact what is impacting your site.