The same thing happened to me a few years ago. The solar reading was stuck at one value for 24 hours. I could not find a way to bulk edit; it's one entry at a time. There is an alternative to using the Data Viewer/Editor.
If you are just editing a few items, the Data Viewer/Editor tool is a lot simpler to use. If you have a lot of items to edit, you may want to edit the appropriate .cat file using a text editor like BBEdit or the TextEdit app on your Mac. Do NOT use a word processor or web editor! You have an April 2023 .cat file called 4_WeatherCatData.cat which you can open and edit.
If you decide to edit a .cat file, be sure to read the section in the WeatherCat Manual just before the Appendices called WeatherCat and Data (Page 180 in the current manual) before you start. If you decide to go this route, I suggest you duplicate the file first, so that if your editing messes up the file, you can always go back to the original and try again.
When you are done, be sure to delete the 2023 4_WeatherCatData.cat.hrs file before you start WeatherCat.
Like I said, the Data Viewer/Editor is simpler to use but I can go faster in a text editor.