With any form controls after the user has entered their input, click Next, click Prev, their input has gone and the defaults are there. Any-one know how to maintain the user input? I'm using v 2.4. Thanks.

If you want to 'retain' the input for the duration of the modules view life, that is until it is closed, then add an action to the objects and capture into a variable.
It would be cleaner to capture into an array but that would probably need an external control script

OK after a quick think about this....
The form objects all have a field in the object properties to write to a specific variable. A vlaue is decalred by default and a variable created on the fly.
I'm thinking that if you declare some global variables at the start up of the module, as a part of slide 1 or even in the base module settings would be OK. Then set a value for these as a default or leave them unset with no value.
When you add the form objects on the slide set the variable used to those you set up earlier.
I've not tried this yet but hopefully the default value you set should be displayed, text ticks etc. **This might be where this idea falls over** When the user changes these the variable gets updated and should retain the value until the module is closed and reopened.

Ah I've made some progress by declaring global variables at the start of the module then using method and variable actions to set and store the input values in a text field. Thanks for your support nickj.