I would try the same with AMPDU disabled. (Not sure if you can set it as it’s greyed out)
But not convinced it will make a difference.
When to turn Optimize AMPDU aggregation Off
You should generally turn Optimized AMPDU aggregation function disabled when you are running time critical applications such as online gaming or VoIP. The reason is that the AMPDU is less efficient and slower by itself. You want faster and immediate transmission of data rather than aggregation through the router.