I have never had any problems with raindrop keeping me signed in. I use it on many devices on different platforms (iOS, iPad, Win, Mac, Web) and once logged in, it stays logged in.

But when I activated 2FA a few weeks ago I need to login about 50% of the times I open the app. I have not found a pattern why/when. For instance, just now when I started my work computer I need to login on the win-desktop client .. again. Most of times I just need to click on the login button coz I _usually_ already are logged in in the browser (so it goes quite quickly) but sometimes I need to login again in the browser. I need to deactivate the 2FA for now.