Okay, so these statistics are from shortly after a boot up without actually sending traffic over the link. That in itself is great as we need these for reference, but could re-do your test and collect the output of "tc -s qdisc" from before and after? It would be great if you could use the dslreports speedtest (see https://forum.openwrt.org/t/sqm-qos-recommended-settings-for-the-dslreports-speedtest-bufferbloat-testing/2803 for configuration notes). And you pretty much use the default configuration, have a look at https://lede-project.org/docs/howto/sqm especially the make sing and dance section to get more mileage out of cake. Also it would be great if you could monitor the router's load while running your test (in the router's cli use "top -d 1" and look at the idle value, if this is too close to zero expect bumpy performance...).
Finally could you summarize how many machines you use and how they are connected to the router?