So if your config is set for 48 can you add more pages ? or is it pages for a lower number as I can't get the pages to work at all and yes I have "Container UI": {
"Show page buttons on container bar": true

and also have sort button installed as well 

Installed v3.11.0

Thanks

Did you forget to reload the mod? I changed mine back to 48 as default and per page, with the show page buttons on bar marked to true and all is working as promised here.

Yes I reloaded it mutiple times and still dont see "pages"

How many pages you see is dependent on a combination of your allotted capacity, and the configured max slots per page. For example, if you add 96 to the Permission sizes config, reload the plugin, and grant the permission backpacks.size.96, your backpack will have 96 capacity. That will automatically show at least 2 pages. If you have set "Max size per page" to lower than 48, 96 capacity will show three or more pages.

If you are using the Sort Button plugin, and you have configured the plugin to show the page buttons on the container bar (you have already said yes to both of these), the Sort Button UI will probably cover up the page buttons, so you will want to set Show page buttons on container bar to false (default) so that it shows above the container bar to avoid overlapping.

Thank you that did it