I got the same problem and it is not related to 17.2 because I had it with previous version, too. When you search the internet you will see that many people seem to have similar problems with this chipset. There are a few suggested solutions but none of them worked for me. I think there is a big problem with the chipset driver.
For me that current situation is like this:
* Connection to wi-fi is established quickly
* Connection quality is normal
* Speed seems to have a huge latency and is very slow (around 10kb/s)
* After 1 minute no data is transmitted anymore
* After 2 minutes the connection is lost and re-established immediately
I have played with /etc/modprobe.d/RTL8723AE.conf some time ago and managed to get a good improvement (up to 40Mbit/s data transfer). Unfortunately, this only worked for 2 minutes. Then the connection was lost again and I never got this speed again.
All solutions that are suggested on the Internet seem to not have a clue what the real problem is. They just seem to try some things out.
Any help to find out what is going wrong and how to fix this is appreciated very much!