this is the answer
Clear the Outlook cache. Sometimes cached signatures or old settings keep causing issues. Clearing and re-adding your signature can fix it.
**To clear cache in Classic Outlook, please follow these steps:**Close the Outlook app.
Press the Windows + R keys simultaneously to open the Run dialog box.
Type the following path into the Run box and press Enter: %localappdata%\Microsoft\Outlook\RoamCache
This will open the RoamCache folder containing the cache files associated with your Outlook profile. Usually, it's located at: C:\Users{User name}\AppData\Local\Microsoft\Outlook\RoamCache
Click anywhere within the folder, press Ctrl + A to select all files, and then press the Delete key to remove them. Alternatively, you can right-click the selection and choose the Delete option from the context menu.
After clearing the cache, restart Outlook again. It will rebuild the necessary cache files from scratch