Are you using an ExcelStyler for styling the columns, or just the formatting settings in the writer?

Both ways, same negative result.

Hi ​@davtorgh, I did a quick test and was able to apply styling on an Excel sheet. If you’re using the ExcelStyler, please take a look at the Feature Information Window of one of your features. Is there anything in the xlsx_row_formatting field? 
What version of FME are you using? I was able to make it work in FME 2024.2. 

Hi ​@saraatsafe,

I’v tried a bunch of times with the ExcelStyler (inserting one, removing it and inserting another one and so on) and, in the end, it worked, but it seems to happen randomly. I’m using FME 2023.2.4.0 (20240416 - Build 23785 - WIN64).

By the way, the font settings aren’t applied to the header row (the first one), but only to the data rows (the following ones).

Sorry for the late response.

Yes by default the font settings from the ExcelStyler will only be on the data when you are outputting the Field Names to excel as heading. I typically apply the heading style that I want in the writer and then style the rest of the data with the ExcelStyler (the styling from the ExcelStyler will take priority for the data).

If you want to style everything in the ExcelStyler, you would want to create a single feature to contain all of the information that you want to end up being the header and then not output field names when you go to write it.

Is there any style information involved in the schema that you are using?