You can't show the last 5 of every user for example. The asset profile.% just combines all the profile gallery entries into 1 gallery then displays the most recent 5 entries from it. Maybe use random order by or something of the sort, but there's nothing available (nor planned) for what you're trying to do.

The demo site has been reset so I've re-applied this configuration and again it is working fine and as expected. Notice the first 2 entries are from Demo User while the rest are from Susan K.

demo.cbdemosites.com/addons/cb-gallery/cb-gallery-module

You can change the limit to whatever you like within the CB Gallery modules parameters. Edit your CB Gallery module then under the Media tab you'll find the paging parameters for media and under the Paging header adjust Limit as needed. You can also turn on paging here if needed.

Edit your gallery module within Extensions > Modules. Next under Media tab under the Paging header set Media to 5 or 10 (it's already default 5). Now set Order By to Date DESC. Next under the Gallery tab set Asset to profile.%. To limit it to photos only you need to disable the other media, which is done under Videos, Music, and Files tabs and by setting their Videos, Music, and Files parameters to Disabled (it's the first parameter under each of those tabs).

This again is working fine locally and on demo site so I've no idea what you're doing wrong or what output you're expecting, but the provided instructions will display the 5 or 10 most recent profile gallery photos shared on your site. If you've 1 user who has uploaded 20 photos then you'll only see that users most recent 5 or 10. If you've 1 user that uploaded 2 and another that uploaded 3 then you'd for example see those 2 and those 3. It's not going to limit it to 5 or 10 per user; there is no functionality for that and no plans for functionality for that. It simply put shows latest profile gallery photos among all profile galleries.

If still not working please PM backend super administrator login credentials and will take a look.