Files show "no activity to show"

I have three folders that have been shared with an outside agency that show normal on my end. However the agency I have shared with says that when they open the folders they only see “no activity to show”. we have tried sharing the folder multiple times and with different people and the issue persists. I had the outside agency try to access the folders multiple times throughout the day and have not had any improvement. Can someone suggest how to fix this?