tiktok algorithm is a mystery

for the past 2 months, ive been posting faceless videos and always used the same background. today i edited a new video, changed the background to a different one and suddenly my video got 140 views in 1h and only being shown in the UK. before, my vids were getting pushed out to at least 1k people in the first hour. tiktok’s algorithm is trult beyond me because nothing else in the content changed except for the background.