HL7812 EVK - GNSS Not Acquiring Satellite Fix (Firmware 5.4.12.2)

I am experiencing issues with GNSS functionality on the HL7812 EVK board. Despite following the standard AT command sequence, the GNSS module is unable to acquire a satellite fix and shows zero satellites in use.
Hardware & Firmware Details:
Module: HL7812 EVK
Firmware: HL7812.5.4.12.2-23.01.0.FreeRTOS.rc2
Baseband: HL78xx.5.4.12.2.RK_03_02_00_22_24731_001.20230330
IMEI-SV: 3511444414114212
Antenna: Active GNSS antenna connected
Issue Description:
GNSS starts successfully but does not acquire any satellite signals. NMEA output shows:
Fix quality: 0 (no fix)
Satellites in use: 00
Position validity: V (invalid)
Events: +GNSSEV: 3,0 (no fix available)
AT Commands Used:

HL7812.5.4.12.2-23.01.0.FreeRTOS.rc2
HL78xx.5.4.12.2.RK_03_02_00_22_24731_001.20230330
2023/03/30 08:42:08
IMEI-SV: 3511444414114212
Legato RTOS: 23.01.0.FreeRTOS.rc2 2023/03/30 05:53:54
atSwi: 23.01.0.FreeRTOS.rc2
UBOOT: 01.03
Apps: RKAPP_03_02_00_22_24651_001__38231c6d829dbf9c71390d591eff7fc36cfd187b
MAC: ALT1250_03_02_00_22_24731_2G
PHY: 0.0.306480
PMP: 315260
AISE: ISE2APP_00_00_00_09

SBUB: 1
SBFW: 1
FPuK1: CBF402DD
FPuK2: 4BE7EB7F
RBUB: 0
RBFW: 0
MCU-Disable: 1

AT+KSRAT?
+KSRAT: 1
OK
AT+CMEE=1
OK
OK
AT+CFUN=4,0
OK
AT+KPATTERN=“–EOF–Pattern–”
OK
AT+GNSSCONF=10,1
OK
AT+GNSSNMEA=0,1000,0,4F
OK
AT+GNSSSTART=0
OK
+GNSSEV: 0,1
+GNSSEV: 1,1
+GNSSEV: 3,0
AT+GNSSNMEA=4
CONNECT
$GPGGA,000011.00,0,00,48
$GNGSA,A,1,00
$GNRMC,000011.00,V,060180,N
6C
$PSGSA,1,0,0,00,3,0,B,0,0,0,0,0,0,0,0,0,0
0A
$GNGST,000011.00,*67
$GPGGA,000012.00,0,00,4B
$GNGSA,A,1,00
$GNRMC,000012.00,V,060180,N
6F
$PSGSA,1,0,0,00,3,0,B,0,0,0,0,0,0,0,0,0,0
0A
$GNGST,000012.00,*64
$GPGGA,000013.00,0,00,4A
$GNGSA,A,1,00
$GNRMC,000013.00,V,060180,N
6E
$PSGSA,1,0,0,00,3,0,B,0,0,0,0,0,0,0,0,0,0
0A
$GNGST,000013.00,*65
$GPGGA,000014.00,0,00,4D
$GNGSA,A,1,00
$GNRMC,000014.00,V,060180,N
69
$PSGSA,1,0,0,00,3,0,B,0,0,0,0,0,0,0,0,0,0
0A
$GNGST,000014.00,*62
$GPGGA,000015.00,0,00,4C
$GNGSA,A,1,00
$GNRMC,000015.00,V,060180,N
68
$PSGSA,1,0,0,00,3,0,B,0,0,0,0,0,0,0,0,0,0
0A
$GNGST,000015.00,*63
$GPGGA,000016.00,0,00,4F
$GNGSA,A,1,00
$GNRMC,000016.00,V,060180,N
6B
$PSGSA,1,0,0,00,3,0,B,0,0,0,0,0,0,0,0,0,0
0A
$GNGST,000016.00,*60

Testing Environment:

  • Location: Bengaluru, Karnataka, India (outdoor, open sky)
  • Duration: 15+ minutes of continuous GNSS operation
    Request:
  • Are there known GNSS issues with firmware version 5.4.12.2?
  • Should I upgrade to a newer firmware version (5.5.x or later)?
  • Additional AT commands or configuration for improved GNSS performance?
  • Antenna specifications or hardware verification steps?

is there any improvement with the latest firmware?
https://source.sierrawireless.com/resources/airprime/software/hl781x-and-hl7845-firmware/hl781x-release-6,-d-,2/#sthash.PY3T2ncn.dpbs

BTW, here says active antenna is not supported:

Lastly, I can see other user can make it work: