Number of servings after import

Hi Jan,
I noticed today that for some imported recipes - including this one from yesterday “https://www1.wdr.de/verbraucher/rezepte/gorgonzola-tartine-mit-feigen-thymian-walnuss-gremolata-und-eingelegten-zwiebeln-100.html” - the overview shows "1 portion" after import, even though the recipe itself calls for 4. When I edit the recipe, it does show a 4, albeit somewhat faintly. If I overwrite that 4 with a 4 and save the recipe, the overview then correctly displays 4 portions. Am I doing something wrong during the import, or are there default settings I’m unaware of?
Thanks in advance for your help, Stefan.