Review toolbar is broken

@viet, could you please have a look at this? Cheers!

03:22 UTC: I have just started doing reviews after seeing this thread and writing the above, and so far everything is fine for me, on a PC using Chrome with lots of scripts.
03:35 UTC: Just completed my review session and had no issues. Has this resolved for anyone who has posted above??

This earlier thread may be related: Lessons not working