Technical Tip: Registration status of managed devices is empty in FortiGate GUI FortiOS v7.6.3

When the FortiGate is on 7.6.3 version or is upgraded to 7.6.3 version, upon checking the registration status of the managed devices like FortiAPs and FortiSwitches from FortiGate GUI under System -> Firmware & registration, it shows empty as shown below:

And when trying to register these devices from the FortiGate and doing the debugs, it shows the device is already registered.

Debug commands :

diagnose debug disable

diagnose debug reset

diagnose debug application forticldd -1

diagnose debug console time en

diagnose debug en

To disable it:

diagnose debug disable

diagnose debug reset

Registering via GUI : 

Under System -> Firmware & registration -> 'Right-click' the device and select Register.

Or: 

From  WiFi & Switch Controller -> Managed FortiSwitch/Managed FortiAP -> Select the device -> Select Register

Registering via CLI :

diagnose forticare direct-registration product-registration -N S124DP3X15000000 -a xxxx@fortinet.com -p LDAP -T "CA" -R "other" -e 1

Account info:
contract_number=[] account_id=[xxxx@fortinet.com] password=[***]
reseller_id=0 reseller=[other]
first_name=[] last_name=[] company=[]
title=[] address=[] city=[]
state=[] state_code=[] country_code=0
post_code=[] phone=[] fax=[]
industry=[] industry_id=0 orgsize=[] orgsize_id=0
version=0 SN=[S124DP3X15000000] existing=1
Prepare to register product into this account.
Do you want to continue? (y/n)y

The output with the debugs on shows something like this:

[113] fds_print_msg: <?xml version="1.0" encoding="utf-8"?><soap:Envelope xmlns:soap="http://www.w3.org/2003/05/soap-envelope" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instanc
e" xmlns:xsd="http://www.w3.org/2001/XMLSchema"><soap:Body><ProductRegistrationForNonFGTResponse xmlns="http://tempuri.org/"><ProductRegistrationForNonFGTResult><RegistrationResp
onse xmlns=""><Version>3.0</Version><Result>error</Result><Error>"S124DP3X15000000" has already been registered.</Error></RegistrationResponse></ProductRegistrationForNonFGTResu
[105] fds_print_msg: lt></ProductRegistrationForNonFGTResponse></soap:Body></soap:Envelope>
[563] fds_send_reply2: Sending 582 bytes data, data2len=0.
[507] fds_free_tsk: cmd=29; req.noreply=1

========Forticare response error========
"S124DP3X15000000" has already been registered.
Registration failed

Upon verifying the same in the FortiCloud portal under Products -> My asset, the device shows as registered.

This is a cosmetic or GUI known issue in FortiOS v7.6.3 version and is fixed in version v7.6.4.