From my personal experience it is not related to the server or the app: I suffered from the issue as well. Root cause is the mobile service of the OEM SIM card (at least here in Germany). Finally I opened the telematic box and replaced the original SIM card with a local one I purchased. Works like a charm, there is no SIM lock or anything, app and bike started talking again after a couple of minutes. It updated battery SOC, diagnosis works as well.