Update on performance issue. I had originally tested with an internet speed test tool and thought the performance was now ok (my last post). However, when I transfer files from my NAS, the 2.4GHz connection is much slower, so there is still an performance issue.
usiong copy / paste to transfer file from NAS to laptop, when connected to the 2.4 GHZ connection the transfer speed (as displayed in windows popup) varies between 356 kb and 1.6 MB/s. When I pause the transfer and switch to the 5 GHz SSID the speed increases to between 14 and 16 MB/s. When I pause it again and switch back to 2.4 GHz SSID speed dropss back to between 356 kb and 1.6 MB/s.