Copy link to clipboard
The 28th is sticking out. It's not under any years and not showing any photos. I tried finding a photo on that date using Bridge.
Most likely it contained a photo, but you deleted it later because you did not want to keep it.
Hmmm, so Lightroom Classic still keeps information on deleted (from catalogue) images? That sounds counterintuitive.
Restarting Lightroom should remove that info. If it doesn't, then that could indicate catalog corruption. Did you try to optimize the catalog?