Here’s Google’s warning from the screenshot as text so that this post can be found better:
Remove risky access to your data
This app or service has extensive access to your personal information and its developer’s information hasn’t been verified by Google. You should remove its access unless you’re sure you trust it.
I am not the original poster, but I am having this same issue. Here is what the “App details” shows for me. (I use insync-headless on my linux fileserver)
Just a little more context around this – at least for me: Having this security warning PREVENTS me from using “3D mode” for google maps. An odd correlation in my opinion, but nonetheless that’s the situation