How to fix google pixel gps not working?

I have exactly the same problem on a new Google Pixel bought from Ebay (presumably old stock). Same result from GPS test.

It is running OS 9, and other devices running 9 (eg a friend's Samsung phone) are fine.

I wonder how many others have this without realising it because in high accuracy mode it will probably get a fix from somewhere, but not necessarily GPS, and not necessarily that accurate (that needs GPS). For instance Google maps will show location OK until high accuracy is turned off (so it then relies on GPS only), but then it won't. Battery saving is also off.

High accuracy is a bit of a misnomer anyway, because mobile towers / sensors can help the GPS fix in various ways, covering gaps etc (sensor fusion), but without working GPS in the first place there will never be an accurate fix.

I am wondering whether to upgrade to OS 10 OTA in case it is a software fault, but am wary of doing so without the supplier's say so as it is under guarantee. Anyway, it is probably a hardware fault.

So, did you find an answer, because I haven't?

Any experience here in the cleaning and re-connecting the GPS cable(s)? (Pixel 4a).

Planning to change my battery, but it is really necessary to have a good gps afterwards. It has had some rain in the past. Maybe some oxidation but its so hard to open, simply testing is not easy. So at battery exchanging time, it would be very nice to solve gps issues before glueing it back together.

I do not see new gps cables here. A new motherbord seems waisting money if that is not 100% sure the cause. Just a new cable seems a better approach but its like nobody has done that before and are the cables not available??

ES, Repair Cafe Bunnik, NL