I can't speak to the issue/fix Jarvis1.0 had, but I can say that I had this same issue with my X4 and will be glad to share my fix.
Was new to Hyrdros and just gave power to my X4. Saw the device in the app and entered WIFI password. Once done, the app instructed me to wait for the X4 to reboot. As I was new to all of this, I wasn't sure how I would know if the X4 was booting, had finished booting, etc. Within a minute, my X4 was breathing red. I continued to wait but the app wasn't reflecting that anything had happened.
After 30 minutes or so, I found documentation to reconnect to the X4 to supply Wifi credentials again. This time, the system rebooted and, within 30 seconds or so, the app refreshed, I could see/control my X4, and it started breathing blue.
I'm an IT guy, I was using the app on my Galaxy Fold 3 which has a very large screen, and I was just certain I had typed the PWD in correctly the first time. Ha. All of that and I still messed it up somehow.
So, in the end, I had simply provided a bad password for SSID during setup and easily resolved by rebooting the X4, reconnecting to it, and then providing the proper password for the Wifi.
These days, I could get straight to the fix but, before, because I was new to all of this, I had no clue what the unit was doing or how long I needed to wait for it to properly reboot itself.
Hope this helps others!