Sale spike reasons. How to find?

PL , niche product with almost none competition ,Average of 12 sales a day on Italy market , suddenly had a day with 36 sales, never happened before (selling for 1 year). I would like to know the reasons. What i checked already:

1. influencer i collaborated before , no repost about my product.
2. Googled my product name , nothing came out except my amazon link and 1 ebay reseller.
3. Searched my product name on tiktok or ig , no new posts.

Any suggestions?