When the weak and the electromagnetic interaction mix, they form the gauge group U(1)_Y for hypercharge Y. This occurs above the electroweak scale, so above around 100 GeV.
In the spaghetti model, it is unclear, when the U(1) group is described, whether U(1)_EM or U(1)_Y is meant. This looks like a major issue!
Update: this is a serious issue, but not a major one. The main results of the model remain valid.