@Excel I use an ArcherC7v2 with DD-WRT and the CAKE or PIE algorithm takes care of the buffer bloat. dslreports gives my network all A's. The TP_LINK AX1500 WiFi 6 Router which costs 80 bucks and is the second router I purchased new ( the rest came from Goodwill, including the C7) is a complete disappointment. Even if I se the AX1500 upload/download to the same values as the AAA C7, I get QUADRUPLE digit buffer bloat on dslreports. The issue is TP-LINK is either using a very bad QoS queuing algorithm, or nothing at all. Imagine the horror when I realized I just paid for a new WiFi6 router which has NO QUEUING ALGORITHMS (and is closed source, so no chance of making use of it via DD-WRT). I will never buy a TP-LINK router brand new again. TP-LINK's router firmware was a complete disappointment, it wouldn't even let me use the appropriate QoS values in kbs until I complained, and they eventually updated the firmware, but the quadruple digit buffer bloat detected on dslreports remains unresolved BECAUSE TP-LINK ROUTER FIRMWARE OFFERS NO QUEUING ALGORITHMS! The AX1500 will sit in a tote and I may check for updates occasionally, but without the CAKE queuing algorithm (which totally and completely resolves my ISP buffer bloat issue) the AX1500, and similar poorly designed TP-LINK hardware/firmware are useless paperweights when an ARCHER C7v2 from 2014 is running circles around TP-LINK's new budget WiFi6 router (exclusively at Walmart y'all)

TL:DR the upload/download values don't matter if the queuing algorithm is poorly designed or nonexistent

P.S. I stumbled across this discussion researching QoS and it struck a chord. I understand the model discussed is not the AX1500, but my input seemed applicable.

@spiralamok News flash: very few OEM firmwares support bufferbloat mitigation measures. It's a sad state of afairs, but you won't find much better with other vendors. Best advice is to buy something that's well-supported by OpenWrt (preferably a stable version) and update form the outset. 

@Excel not sure if it's an option on your router, but I have had some really good success by turning off QoS. Granted, I have gigabit internet, so turning off QoS is likely enabling NAT boosting/acceleration.

For wifi devices that are latency sensitive, setting speed limits/bandwidth limiting individual devices that are particularly latency sensitive is another option. In my setup with an AX4400, I can get full gigabit speeds hardwired with low loaded latency, and my wifi devices are seeing only 5-15 ms increases under load after adjusting their speeds.

Your situation is kind of the opposite of mine because your ISP connection speed may be the slowest link in your network. For bufferbloat, what is working for me is identifying the slowest connection speed in the network for a given device, and then bandwidth limiting that device by subtracting 25 to 75 Mbps from its max speed. As an example, I have a device that can get 250 down/175 up and I have bandwidth limited it to 175 down/150 up to get the lowest buffer bloat latency numbers based on the waveform.com bufferbloat test. This device is used for gaming, so I don't care that much about the raw speeds. Generally, QoS and bufferbloat elimination will come at the cost of reducing max bandwidth.