While working on the project, the indexes are not getting generated or partially generated. I have tried adding indexes as keyword and also as sub-keyword under the main default index, which I have renamed (PCC_VoySchedule) as per project requirement. But both the cases, the result shows partially generated index.
Please refer the below screenshot for your reference.
Are all your topics included in the table of contents? They must be in the table of contents to be included in the generated output in Robohelp 2020. If you don't want them to display in the ToC, you can set the "Hide in output" checkbox in the propertis for the ToC entry.