Job Submission Form Fields not allowing any entries

Hello,

After implementation of the plugin and the creation of the Job Submission page, the fields (such as Company name, etc) are not accepting any entries. When clicking on it a window opens for inserting a file from the desktop (image, doc, etc). Also the mouse cursor shows a prohibition symbol. I noticed it with Theme called Hestia, but also with Twenty Twelve and Twenty Seventeen (at least here it is possible to add text but still the symbol is there when scrolling over the fields and preview button is not working).

Is this a setup issue or related to the themes?

Any solutions?

Many thanks in advance!