This is because according to user complaints made in Apple’s Support Community and Reddit, it seems that syncing your device with an M1 Mac could result in apps on your iPhone or iPad to stop working. Users are reporting that after they synced their devices, third-party apps no longer seem to work. They were also unable to install or update their apps from the App Store.
According to one user, “After I sync my iPhone X (on 14.3) with my M1 MBP (on 11.1), no third-party apps will open. Can’t install or update from App Store either; the progress circle will fill up and then immediately turn into the “cloud” download icon.” This seems to be related to the M1 Mac because another user claimed to have experienced the same issue, but that issue was fixed when they resynced it with a non-M1 powered Mac.
“On Accident I connected iPhone and MBP M1 via WLAN and synced…. Apps stoped working immediatly. Then connected to my old MBP (2012, latest Calatina) and synced. Apps are all working again.” These reports have been appearing since December 2020 so hopefully Apple is aware of it and are working on a fix.