You may diagnose these network settings by activating and deactivating the wireless network interface from the Terminal, which shows some diagnostic messages:
You may diagnose the network adapter status with commands:
sudo ifdown wlan0
sudo ifup wlan0
I also want to see the results of this command:
I'm thinking it could also be packet loss, it certainly sounds like it.
Packet loss can be caused by a number of factors, including signal degradation over the network medium, oversaturated network links, corrupted packets rejected in-transit, faulty networking hardware, maligned system drivers or network applications, or normal routing routines.
Some network transport protocols such as TCP provide for reliable delivery of packets. In the event of packet loss, the receiver asks for retransmission or the sender automatically resends any segments that have not been acknowledged.
You might want to check if there is any interference with like a phone or a microwave or even possibly a lamp. I know it sounds stupid but my lamp for some reason was causing some interference with my router, that can all lead to packet loss.
I see that you have solved your issues, but this may be a possibility or a factor of the problem. I had the exact same issue as you, and it turned out all it was, was severe packet loss, and I did some commands and moved some things around and it works like a charm.