Translated with Google Translate from Bluesky Lee's post
Check your system as follows.
(Translate my reply with Google Translate!)
1. When you run the app, the first screen appears
Press the 'Help' item, and click the 'Device Check' in the sub-item.
Click (click) to run 6 checks!!
( 6-axis, 3-axis, LED, camera, etc ....~~~)
=> Look at the ok...or fail result...
If the camera check fails...
It's possible. (Firmware upgrade fails, the app screen does not switch to the moderator (camera screen) mode, and some other issues...
2. Check if Wifi and data communication (4g or 5g) are running on the smartphone at the same time. as a bonus
In the Wifi list, check if the wifi transmitted from the remote control is shown in the wifi list of the smartphone.
==> <FIFISHRC_xxxx cannot connect to the internet)>...
3. And run the app.
=> If you click the 'Connect' button, 'Connect' is executed and check if the mode is converted to the moderator (camera screen). If the conversion does not work, the rov body.. that is, it may be a hardware problem or malfunction.
4. After setting the app with other smartphone models of your acquaintances or family members, try to see if you can control the rov normally. (Don't just try it with your iPhone!)