When opening a previous design created in DSPCB you may find certain functions/tools do not allow you to edit everything. The reason is that parts of the DSPCB design are 'fixed'.
It is recommended that you start using your DSPCB design in Pro by "unfixing" everything, this is simply achieved using Edit -> Fix and Unfix from the menu bar.
In the new window select "Unfix", "Select All" and "OK"
Everything is now editable.
Items can now be selectively "Fixed" and "Unfixed" as required.
Alternatively as "all manually laid tracks are automatically fixed for router" you may change the default settings in Pro to work better when continuing with a DSPCB created design.
Go to Settings - Preferences - PCB Interaction and ensure the checkboxes highlighted in the image below are not selected.
Note. As with all settings you may wish to change/ select these options again at a later stage of the project development.