Like @Anonymous suggested, you should add ".Text" at the end of the TextInput control's name. But please notice the column type of Jan column. It need to be a text/number column type to make this work. If it's other column types, please tell the column type and we will suggest the syntax to use.
Also notice that you need to include all the required fields from SharePoint list while patching.
Community Support Team _ Mona Li If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.