Why are the custom events of Firebase analytics not shown on dashboard?

Question

I have integrated firebase into my Android application. I am sending custom events as follows :

 Bundle bundle = new Bundle();
        bundle.putString("First Category", "First catValue");
        bundle.putString("sub Cat", "sub CatValue");
        bundle.putLong(FirebaseAnalytics.Param.VALUE, "value");
        firebaseAnalytics.logEvent("My Custom Event", bundle);

None of my custom events show on events tab on firebase analytics dashboard.

I have taken look in some questions already asked like this one : Android Firebase Analytics Custom Events Reporting in Console

But couldn't solve my problem as I tried some of the suggestions there, like it was suggested to test with more than 10 users to be able to get the custom events which I did but nothing is shown in the events tab.

I debugged using following commands:

adb shell setprop log.tag.FA VERBOSE
adb shell setprop log.tag.FA-SVC VERBOSE
adb logcat -v time -s FA FA-SVC

My events are getting logged on command prompt but not getting reflected on firebase dashboard.

Am I sending custom events wrongly ? Do I need to configure anything on firebase dashboard to get the custom events ?

Update :

When I debugged using commands :

 adb shell setprop log.tag.FA VERBOSE
    adb shell setprop log.tag.FA-SVC VERBOSE
    adb logcat -v time -s FA FA-SVC

I found this important log stating Name must consist of letters, digits or _ (underscores).

Then I changed my event as below :

 Bundle bundle = new Bundle();
            bundle.putString("First_Category", "First_catValue");
            bundle.putString("sub_Cat", "sub_CatValue");
            bundle.putLong(FirebaseAnalytics.Param.VALUE, "value");
            firebaseAnalytics.logEvent("My_Custom_Event", bundle);

Then I enabled debug view https://support.google.com/firebase/answer/7201382?hl=en&utm_id=ad as suggested by adbitx in answer below, then events started showing.

Answer 1

Update :

When I debugged using commands :

    adb shell setprop log.tag.FA VERBOSE
    adb shell setprop log.tag.FA-SVC VERBOSE
    adb logcat -v time -s FA FA-SVC

I found this important log stating

Name must consist of letters, digits or _ (underscores).

Then I changed my event as below :

 Bundle bundle = new Bundle();
            bundle.putString("First_Category", "First_catValue");
            bundle.putString("sub_Cat", "sub_CatValue");
            bundle.putLong(FirebaseAnalytics.Param.VALUE, "value");
            firebaseAnalytics.logEvent("My_Custom_Event", bundle);

Then I enabled debug view https://support.google.com/firebase/answer/7201382?hl=en&utm_id=ad as suggested by adbitx in answer, then events started showing.