You have to have changed something.
May be you changed the mode (exclusive, inclusive,) or the composing of masks (union, intersection...)
Or may be you have created a Ptah independent of the module and have not applied it to a module.
Paths and modules are independent, you can create a path and apply it to several modules.
If you create the path under the module mask (at the right) it is automatically applied to that module, and selects the interior.
Be sure there are selected figures in the module mask.