Trouble about multiple device in one phone

My project is about the control power in meeting room. By use sensor DHT11 and Current transformers (CTs) to get power input and re-check. Sample 1 floor have 4 room and I’ll test 4 floors 16 room. But I’ve try to use 1 mobile phone to control 16 device(room) > for group to 4 floors (44) and group floor to 4 tags (44). In my project already have tag 1-tag 4 and floor 1 - floor 4. I use a 4 SuperChart and 4 Styled Button for 4 tags. And I use 4 SuperChart 8 Gauge 4 Styled Button for each floor.
My trouble is when I’ve try to switch between tag or floor my app always crash. And it didn’t save my last edit. I’ve re-install application ,re-open ,reboot. It seem like the same

My device : iPhone XS Max iOS:13.3 (Lastest) Application Version : 2.26.1

It sounds like this is ultimately going to be a business application that you are testing with the free (non commercial) version of Blynk to see if it will be appropriate for your needs.

I’d recommend heading over to and opening a dialogue with the guys from the commercial side, as I’m sure they will be happy to answer your questions. If this is an issue caused by restrictions imposed by the free version of a Blynk (which I suspect it is) then they should be able to advise on that.

@Pavel - one for you?