In your screenshot you've Tx bursting enabled, this isn't the correct setting for best speed.I continue to collect success stories from my settings recommendations. Some, including me, have even better performance with Asus Factory than running Merlin. As I have stated before, my goal was to make my network simple enough for someone with basic network knowledge to fix something in case I get sick (or die) and can't manage the router. I feel that I have succeeded in spite of some (your) negative comments.
You need to disable it and try.
On 2.4 Ghz Wireless mode should be set to auto but, very imp thing is to have, the bandwidth set to 40 mhz so that the router falls back to max link rate possible even in crowded environment.
For me it's on 173 mbps since my environment is slightly crowded.
But I do agree with you, that the latest stock firmware is better than current Merlin's firmware.
With Merlin's current 384.17 firmware I experienced some bugs where my speed on Samsung smartphones would crawl at 20 mbps and the phone needed a reboot to fix it.
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