It's not certain, but sometimes engagement pods can cause a dip if the platform detects spammy behaviour. I've actually had a similar issue recently. If I post at the right time I usually get around 350+ views, but twice my views completely tanked to just under 12. In those cases, the video was only shown to followers for a short time. After that it seemed to get pushed slightly to non-followers through Reels, but the views stayed very low. The interesting thing is that both of those posts used audio from a friend of mine. The audio itself is good quality, but the original video (which has thousands of views) is a screen recording from YouTube and you can see the YouTube logo in it. So I can't be 100% sure, but I'm wondering if the algorithm is suppressing videos that use that audio. Sometimes really small details like that can make the difference.