Guild Wars 2

I completed this path today for the first time, received the standard ’You’ve done a dungeon path’ reward, but no specific ’You’ve done this path for the first time’ reward. Also, my achievements panel is not showing the path as completed. I have now completed the path for a second time and still no achievement.
Screenshot attached shows missing achievement at completion of path.

Hi,
I have been playing GW2 for the last week or so on my laptop, running at top graphics settings generally at around 60fps (range of maybe 58-62 with the exception of daily events and the like).
Today I logged on and have been getting 10-12fps with the same settings, without having changed anything on my laptop otherwise – the only thing I have done since last playing was to install Civilization V via Steam but that was running fine and was not running at the same time as GW2 so I’m not sure that would be a problem.

I have run a full virus scan, I have run disc optimization.

I am running:
Intel i7-4710MQ CPU @ 2.50GHz
16GB RAM
Windows 8.1 64bit
NVIDIA GeForce GTX 970M

Would really appreciate any suggestions about why this might be happening all of a sudden.

Many thanks