It does seem to look like a hybrid, but my burr oak in its first year or two did have some reddish fall color. After a couple yrs it's just colored like you say -- dull yellow-brown. More info:

https://kb.jniplants.com/hybrid-swamp-bur-oak-quercus-schuettei/

Even the lobes seem to be a bit rounded... the link you posted is of a swamp white oak and a burr. I suppose that's a possibility since the swamps do color up nicely.

It's planted in a bit of a wet spot (late winter until mid-spring) but I am trying to ameliorate that by improving the drainage

I have a bur and a few random leaves have good color like shown above from time to time. The rest is very blah as far as fall color. As far as I can tell your tree's leaves look like bur oak leaves, but I am far from an expert.