I first noticed the problem a few days ago. Not in the alerts drop-down, it was when posting a reply.
I checked my preferences, can't find anything wrong there.
If you go and download Firefox Quantum right now, you’ll immediately notice the difference, accompanied by a feeling of mild euphoria.
Our designers created a system that scales to more than just current hardware but lets us expand in the future.
There’s more that could be said about all the amazing work that went into Quantum, or about some of the exciting stuff in the very near future, but at this point you should stop reading and download Firefox Quantum, because it will make you happy.
Your last screenshot shows what I assume is your computer clock set at 4:07:58 BST on the left, but your forum timezone on the right is UTC.
Okay. Your choice.