MicrosoftHi,
What's the right channel to provide feedback on the new dynamic array features in Excel in insider builds? We have an issue where our custom functions (XLL functions created using ExcelDna) are occasionally detected by Excel as being array functions and get "converted" to CSE-array formula. It happens randomly and I have not found any way to fix files affected by this issue beside starting from an earlier backup of the file, or using a version of Excel that doesn't have the new dynamic array feature enabled.
I used the feedback button in Excel and also posted it here https://techcommunity.microsoft.com/t5/Excel/Dynamic-aware-Excel-incorrectly-flagging-our-custom-XLL/m-p/291362#M22091 but I'm worried this will eventually hit customers using normal release builds of Office.
This creates a host of problems for us - our custom functions are RTD functions, and there's a bug or limitation in Excel where the RTD server does not disconnect when used in an array formula ( https://gist.github.com/govert/03df749f38b9582b1217). To ). To be clear, our functions are not array functions, however since Excel *thinks* they are array function the RTD server does not properly disconnect from the cell.
I think the root of the issue is that Excel looks at the return type of the function to decide if it's a function that can potentially return an array, and since the return type is just "object" it suddenly decides to make the cell formula an array formula. As per: https://support.office.com/en-us/article/dynamic-array-formulas-in-non-dynamic-aware-excel-696e164e-306b-4282-ae9d-aa88f5502fa2, "Whenever you write a formula in dynamic aware Excel, it determines if that formula has the potential to return an array. If it could return an array, we will save it as a dynamic array.". What I don't understand is why it randomly happens, and whether or not we can avoid this...
