Not sure why people are complaining about this chapter. Ritsu not taste testing his porridge can be explain with simple beginner logic: "It's just a porridge." Plus, he only said the porridge is "not very good", so it's not necessarily bad, most likely just bland and still edible, hence Uta happily eat it. If this chapter had following the trope in the usual manner, she would be making a disgusting face, and Ritsu would just spit it out when he taste it.
PS. Uta is so cute as always. And, does mom look younger in this chapter than the previous ones?