The image in first post that you provided does not provide info. (I.E what is missing? )
We have no way of knowing what locations you have added using the WPSLP plug-in. (If you were a MySLP SaaS customer we could see the back end and provide more detailed assistance)
Do you have a staging or dev site? Try this Since you have the Power add-on
Export the locations to a csv file and convert them to a google or excel sheet. Check to see if all the locations are there. If not you could
1) Delete the old locations and re-import as a properly formatted CSV file. If you do delete all locations and re-import you will need to delete the sl_id column from your sheet and thenconvert to csv file.
2) Second suggestion. Export fix or add what you need , check that the sl_id is accurate and matches and use the duplicate update option under import.
More detailed instruction are in documentation
Again I would only delete on a staging site first. Always make sure you have a full back-up before performing any operations.