I reported this as a possible bug in the app but posting here too in case it’s a different problem. When I compile a dictionary using the latest Mac version (Dec 23), the build fails the transporter checks because it says that it’s missing various icon files, including the 1024x1024 size. They are there in what I provided to the app, but when I run the “build iOS app” the missing sizes aren’t included in the log file, so I suspect they aren’t being compiled by the program. However, if others have found a workaround for this I’d love to hear it!
I have seen a similar-sounding issue, but for Android. It wasn’t actually to do with icons at all, but the folder location. From main menu → Settings / Default Folders. Might be worth checking that the folders are 1) the correct ones 2) have write permissions for the account in use 3) are not UNC paths.