I've never seen this behavior before. I selected a number of images and then typed in a headline text. When I moved to another field PSU then placed that text in a number of images but not all. I then selected smaller batches but it still didn't complete all of them. My last two attempts I selected 5 images and all but the 5th completed.
I doubt it's a bug but am curious why this might happen so I can avoid in future if it shows up again. Maybe something with the RX100 files?
PSU 2024.1.1.6414 and the version I had installed just before. All are Sony RX100 RAW and jpg files on Macbook Pro 16 Intel with Ventura.