USB Drives Don't Automount / System Drive Does Automount After Update

Morning all, hate to start my forum life with a problem but here we are :D

I have Kali permanently installed on a laptop. System drive is encrypted, password needed to decrypt at boot.

Usual behavior is that the laptop boots fine, I login, and then whenever I put a USB drive into one of the USB ports Kali automatically mounts it and makes it available in Places. The main system drive is also in Places, listed as 'Computer'.

I did an 'apt-get update && apt-get upgrade' yesterday and everything seemed to go fine.

However, I've noticed today that Places now includes drives with the little eject symbol next to them called 'boot', 'efi', and 'Filesystem root' - delving into these they appear to be the various partitions on the internal SSD of the laptop into which Kali is installed. I've also noticed that USB drives don't automatically mount any more when I plug them in - I can still manually mount a USB drive, but then when I try to unmount it using 'umount' I get a message to say that the drive is busy.

Did the behavior change intentionally, or is something somehow screwed with my install? Any ideas where I start troubleshooting this?

Thanks :)