Hmm, that’s not normal - though bluetooth is only good for about 10m line of sight.
RF interference can also decrease the effective range - anything in the 2.4GHz region can have an impact: Microwaves, WiFi, and USB 3 devices have all been known to cause issues with bluetooth, as well as the shielding from anything metal being in the way, such as a metal Pi Case.
What BT device are you using? And what else do you have near it?
The plastic bottom of the Neo case should allow it to still work with BlueTooth, just to help isolate the cause of the issues could you test it again without the Neo case to see if anything changes? That way you can rule the case in or out as a contributing factor.
If it’s any consolation I have that same case and experience a similar sort of Bluetooth drop-off. Granted, I haven’t tested it without the case, but it might be worth trying it like Trent suggests just for testing. I’m OK with the limited range myself for my purposes.
It does appear that the bluetooth range on the Pi 4 is rather limited, that seems to be the general consensus out there. The Pi Zero W, however, is reported to have an excellent bluetooth range.
The Pi Zero WH arrived today (finally in stock, yay!), and I’m glad to report that it discovered and connected to all the Mijia Bluetooth Temperature/Humidity sensors I have scattered around the house, both inside and just outside the house! Go the mighty tiny Zero!!!
@Jono if you’ve still got your Pi 4 setup, try disabling the ethernet port (I don’t have a Pi 4 myself to test, but this should work I think)
ip link set eth0 down
There’s also an older article on the Core site here that uses a different method:
My theory as to why this might work is that ethernet on the Pi 4 is actually via USB 3.0 - USB 3.0 can cause some nasty interference with bluetooth devices that really kills the range. Thus disabling the ethernet adapter (and making sure to only be using the USB 2.0 ports and not the blue 3.0 ports) might reduce the interference and improve the range of bluetooth on the Pi 4.
I do have the Pi 4 booting off a USB 3 stick at the moment, which is plugged in to the USB 3 for the extra speed. Will experiment with disabling the ethernet port first, then see how I go with not vacating USB 3 port.