I have a Phantom 4 Pro v2.0 that is new but purchased about 2 years ago.  It came with the non-plus remote but I purchased the plus remote separately.  
Plus Remote:
I upgraded all the firmware in the plus remote, controller and even the batteries.  (My end goal was to meet RID compliance).  I also updated all the databases the latest.  The plus remote now shows RID serial number on the controller/about screen and confirms that all software is up to date including the DJI Go 4 app at v4.3.60.  I also noticed on a status screen that popped up the message "Remote ID Functioning Normal" so it sounds like the RID is working although there is no means to confirm this.  Since this is complete, now I get an error message as soon as I connect to the controller that "Battery not installed properly.  Unable to take off.  Check and re-install battery."  I have two additional (new) intelligent batteries and they all do the same thing.  The batteries are seating correctly.  I even have checked the battery status screen on the remote and it states "Connection Ok."  I used a dry paper towel to wipe the contacts in the drone and the batteries but this thing is spotless and clean.  (It's never been flown and always kept in a hard case).

Standard Remote:
I decided to send the drone back to DJI for evaluation.  To put the original remote with the drone to send it back, I removed the SD card from the drone, I linked the original remote to the drone, then I performed all the firmware updates mentioned above including the DJI Go 4 app on my iPad to v4.3.60.  When go to the controller/about screen on my iPad, it shows all the same F/W versions including databases.  But it does NOT show the Remote ID Serial number.  It only shows the controller and remote serial numbers.  The other difference with the original non-plus remote is that the "Battery not installed properly..." message doesn't display and I can start the motors.  I have done this multiple times successfully.  I also rebooted the drone, remote and iPad multiple times as well and can't get the remote ID serial number to display on the controller/about screen as it does in the plus remote.  I also pulled each battery out and put them in multiple times and not once did it give me a battery error.

1.  Why does the plus remote generate the "battery not installed properly..." message but the non-plus remote does not?

2.  Why does the plus remote show the remote ID serial number in the controller/about screen but the standard controller doesn't even though everything is the exact same regarding firmware, databases and DJI Go 4 app version?

Thanks in advance for your assistance.

Regards,

Mark

Hi there. Thank you for reaching out and we're sorry for the trouble that this has caused. Please try to reinstall the DJI Go 4 app on your mobile device and please download and install the version on our website. After that, please enable the location services on your mobile device then run the app then check if you can now see the Remote ID details. Regarding your remote controller with a built-in screen, please download the DJI Assistant 2 software on your computer then update/refresh the firmware of the aircraft also perform an update on your controller by downloading the firmware package on this link https://www.dji.com/downloads/products/phantom-4-pro-v2 then check if the behavior are still the same. We will wait for your response. Thank you for your cooperation.

DJI Paladin Posted at 1-30 00:37
Hi there. Thank you for reaching out and we're sorry for the trouble that this has caused. Please try to reinstall the DJI Go 4 app on your mobile device and please download and install the version on our website. After that, please enable the location services on your mobile device then run the app then check if you can now see the Remote ID details. Regarding your remote controller with a built-in screen, please download the DJI Assistant 2 software on your computer then update/refresh the firmware of the aircraft also perform an update on your controller by downloading the firmware package on this link https://www.dji.com/downloads/products/phantom-4-pro-v2 then check if the behavior are still the same. We will wait for your response. Thank you for your cooperation.

Dear DJI Paladin,

Thank you for your directions.  I found that all my issues were resolved by downloading the DJI Assistant for Phantom and "refreshing" the current/latest firmware drivers on the controller via USB connection.  This resolved the battery issue.  I also found the other problem you identified as being the missing RID on my non-plus controller - my location services were turned off.  When I turned these on, the RID began working correctly.

Thanks again for the quick and accurate response!

Respectfully,

Mark

Mark Drone Guy Posted at 2-3 03:43
Dear DJI Paladin,

Thank you for your directions.  I found that all my issues were resolved by downloading the DJI Assistant for Phantom and "refreshing" the current/latest firmware drivers on the controller via USB connection.  This resolved the battery issue.  I also found the other problem you identified as being the missing RID on my non-plus controller - my location services were turned off.  When I turned these on, the RID began working correctly.

Perfect! We're glad that you have managed to isolate the issue that you experienced. Feel free to contact us if you have further inquiries. Happy flying always.