I'm facing a problem where external links are counted as 0.

Until two days ago, 300 external links were displayed in Search Console, but suddenly they are displayed as no data and 0 external links. But the important thing is that the main keyword ranking also dropped sharply. Are there any other cases where you are facing this issue?

Also happened to me, but the rankings haven't dropped yet. The links are still indexed.

i can confirm the same for many websites,
you might want to check this as well: https://www.seroundtable.com/google-search-console-links-report-decline-37477.html
nothing to confirm yet, a bug or something else