I’m sure that’s very frustrating. 
This forum is for people using the Samsung SmartThings ™ home automation platform, so all of the questions and answers are assumed to be in that context. It is a very active forum, so it often comes up near the top in general home automation searches, but it is not a general home automation forum. Flo used to have a limited IFTTT integration that could be used with SmartThings, but they killed it about 6 months ago, so I’m afraid there won’t be many people who can help you here. 
That said, the issue you describe with showers is quite common with that product, and your best bet is to contact Moen support.
If you’d like to see what forum members here have said about Flo back when there was an integration option, see the following thread, but again remember that all the questions and answers are within the context of the Samsung platform:
Has anyone tried Flo or can recommend any other smart water leak detection system?
If you’d like additional independent resources you can also try the Reddit home automation subforum, which is brand-agnostic: