Extremely SLOW 2.4ghz Wifi on R8300 but not on R6700v2

I recently took out of service my R6700v2 router and put in a new R8300 in its place.  Everything seemd fine until my son complained that his wifi was slow.. I spent several hours checking his laptop out and all the drivers were the latest and other thatn 2.4ghz being very slow nothing else was wrong.

I then checked with my laptop on 2.4 and it was so slow on speedtest.net.  If I tried 5ghz I would get speeds of over 111Mbps,  my wired pc was getting over 125Mbps but the 2.4ghz was barely getting 1Mbps and more often less than that.

I shut my R8300 off and put the R6700v2 back into the network.  After doing all the necessary checks to make sure the network was back up I did speed tests again.

2.4ghz = over 50Mbps on my son's laptop

2.4ghz =  over 75Mbps on my laptop.

5ghz   =  over 118Mbps on my laptop

All these checks were done using the same local destination server.  I did multiple tests to the same local server on all devices and the results were nearly the same.

I checked all the drivers on both laptops and everything was up to date.

I then put the R8300 back in the network and removed the R6700v2.  All 5ghz speeds were nearly identical to the R6700 but the 2.4ghz speeds were in the toilet again.  I have about 5 wifi enabled outlets in the house as well as a Google mini that are running on 2.4 but that did not change when I went from one router to another.

I can only assume the R8300 is the problem.  I checked that the R8300 was at the most current firmware and it is.