Hi @Luc Zwartjes ,
Welcome to Microsoft Q&A forum.
According to your description, seems that you are encountering issues about Outlook for iOS, right? If so, please kindly understand that here we mainly focus on general issues about Outlook desktop client and know little about Outlook for mobile device, the supported products are listed over here https://learn.microsoft.com/en-us/answers/products (more to be added later on).
So, in order to better solve your issue, it is suggested to post a new thread to the dedicated forum for Outlook for iOS. The reason why we recommend posting appropriately is you will get the most qualified pool of respondents, and other partners who read the forums regularly can either share their knowledge or learn from your interaction with us.
Thanks for your understanding and hope your question will be resolved soon.
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