Thanks for summing it up @polina.buriak 
I just wanted to give a quick heads up of what I found out.
Some Apps have issues getting the location transmitted correctly from Leafbure NTRIP Client (for example ArcGIS Field Maps or Quick Caputre). See also this thread: Reach RX and Field Maps on Android - #5 by julia.shestakova
With an old version of ArcGIS Field Maps (called ArcGIS Collector) it worked properly though. I am talking to the ESRI team to find out more about this.
However, I found a solution to connect with the RX directly in the app without losing the fix (and the connection to Emlid Flow in the background). Therefore, the battery settings of Emlid Flow app have to be changed. This can be done in the Android Settings → Apps → Emlid Flow → Battery → Set mode to “Not optimized”
See also following screenshots (in German Though):
