I'm not able to add a specific SSID to SAVED SSIDs ... missing ADD button.

If you open the website with a device with a small screen, you have to open the website in desktopmode to access everything. The mobile view is more simplified.
I see now that on SSID when you add manually it works fine, but when you "Clone Selected APs" it ignores the "Number", and clones it 60 times.
Clone selected APs is different to adding SSIDs manually. It will fill the list until it's full.
But I see why it can be confusing, I added it on the todo list for the next update :)
Closing this issue as inactive, feel free to reopen if necessary.
Most helpful comment
If you open the website with a device with a small screen, you have to open the website in desktopmode to access everything. The mobile view is more simplified.