Here3+ GPS issues

I am facing some issues with my Here3+ GPS units. They are brand new and have just been installed on a new drone a few days ago.
2 have been installed on a quad drone with a Pixhawk cube orange +.
They are somehow stuck, they are showing solid white lights only.
1 of them has only 3 LEDs turning on, not all 4.
They don’t even show up on CAN, but the compass is shown in one of them.
Please advise on how or if I can troubleshoot these GPS units.
Thank You.

I assume you have had a good look here Here 3 Manual - CubePilot @philip any thoughts

I have, thanks for the link. However, my issues have not been solved. I have used many Here3 and Here3+ GPS units and this is the 1st time I have faced such issues. Please advise what should be done next. Thank you.

Did you sort this out Trushant?