In Discovery, instead of honorable warriors, the klingons are a bunch of sneaky backstabbing and coward warriors.

Like they are in TOS?

They also don’t look like klingons at all

Are you similarly upset by the change in appearance the occurred between TOS and TMP?

and architecture

Architecture? I don't know, the House Mo'Kai fortress we see in season two doesn't seem all that out of place. The rounded towers of the capital city seen in ENT is a greater divergence than anything we see in Disco. But that's also fine, because architectural styles change over time.

the speak like their mouth is full of potatoes

And apparently, according to experts in the language, that's the best Klingon has ever sounded on screen. Not really sure how that qualifies as a lore thing, though.

they make ships out of coffins.

One ship. The home of a cult leader.