Something is changed in TOS sw since last month update(automatic) and for them, if they cant replicate at their high end computers then problem doesnot exist...
And you changed nothing at all in your home setup? No router changes or anything else? This is a network issue plain and simple. Is the computer you're using windows or Mac? Install any new firewall or antivirus software?
Tried something as simple as cycling your router? It's definitely a network problem but without being there it's impossible to know if its with your computer or with your router. It's entirely possible its a TOS specific issue but my gut doubts it.