Some of the films in a catalog item are locked
I'm researching digitized films in the on-line catalog: United States, Virginia, Montgomery - Land and property; General index to deeds, 1773-1933; deeds, 1773-1868; wills, 1773-1797; catalog # 373892 (https://www.familysearch.org/search/catalog/373892). The films for the general indices, e.g. 32604, are locked to internet access. However, the films for the deed books themselves, e.g. 32608, are accessible. It seems odd that the indices are locked but the actual content is not as they are all from a single author. Are those permissions correct?
Thanks for any clarification.