Using multiple ESP8266 boards

Good Day everyone, I am new to the community and somewhat new to Blynk but have had a working code before 2.0 and replaced with a working code on the new format 2.0. We have a condo that I was using 4 ESP8266 D1 mini with relay boards to control light in the unit. All was working fine until about 2 months ago I noticed (using cameras at the unit) only one device would work. I did a visit to the condo and found if all 4 are online, only one works. If I only have one online it works fine but as soon as a second unit is online, it takes over and the first unit can not be controlled, same outcome with the other 2 units. Long story short I did some reading about using different authorization codes for each D1 mini but using the same program code. I have seen some talk about this so my question is, how or will this change my device count on my account and what would be my best option?
Dave

Each device needs to be an actual device from Blynk’s perspective, appearing as a device in the console/app.
This means your device count will increase from 1 to 4.
Each device has its own unique auth code, and these need to be used in your sketches.

Pete.