This sounds like the same problem that is being discussed in this topic: Mon & Event buttons.
We are not sure how the app is getting into this state. Sometimes signing out and back in will get things going, but if you just signed in, that probably won’t do it. Sometimes removing and re-installing Coastal Explorer will do it.
We have seen this happen on some of the devices we use and thought we had it figured out and fixed in build 54, but apparently not so we’ll keep working on it!