It sounds like you're experiencing an issue with your Logic App in Azure. Here are some steps you can take to troubleshoot the issue:
1. Check the Azure Service Health: Check the Azure Service Health dashboard to see if there are any known issues or outages that could be impacting your Logic App. You can access the dashboard from the Azure portal by clicking on "Service health" in the left-hand navigation menu.
2. Check the Logic App status: Check the status of your Logic App in the Azure portal. You can do this by navigating to the Logic App resource and checking the "Overview" tab. If there is an issue with the Logic App, you should see an error message here.
3. Check the Logic App runs: Check the runs of your Logic App in the Azure portal. You can do this by navigating to the Logic App resource and clicking on the "Runs history" tab. If there are no runs showing up, or if they are failing, this could indicate an issue with the Logic App.
4. Check the Logic App triggers: Check the triggers for your Logic App in the Azure portal. You can do this by navigating to the Logic App resource and clicking on the "Triggers" tab. Make sure that the trigger is set up correctly and that it is still enabled.
5. Check the Logic App connections: Check the connections used by your Logic App in the Azure portal. You can do this by navigating to the Logic App resource and clicking on the "Connections" tab. Make sure that the connections are still valid and that they are not expired.
6. Check the Logic App logs: Check the logs for your Logic App in the Azure portal. You can do this by navigating to the Logic App resource and clicking on the "Logs" tab. The logs may provide more information about any errors or issues that are occurring.
If you still cannot see the flow in the designer or see the Flow in runs history after performing these steps, you can try contacting Microsoft support for further assistance.