I've been having this ongoing issue for months where I publish for Dev and the flow view shows up. Randomly, a few days later, one of my developers messages me to tell me the flow view icon has disappeared. I have to republish the file each time to get it to reappear (sometimes more than once).
Sorry to hear about the trouble. We'll need to test this on our end, so will it be possible for you to share a sample file and the published link on which this is happening? Could you please also confirm if you have tested this on a different browser to check if it's working on a different browser or not?