its acceleration that causes them to drop out of EV mode, when the weak EV drives cant produce enough power. Can you accelerate all the way to highway speed in real world driving without it dropping out? for some yes, for many no, from the guardian article:

"Even when the cars were driven in electric mode, the analysis found that levels of pollution were well above official estimates. The researchers said this was because electric motors were not strong enough to operate alone, with their engines burning fossil fuels for almost one-third of the distance travelled in electric mode."

The manufacturers dont list this admittedly complicated crossover, so you cant say whether one does or doesnt from a spec sheet. The aggregate data is clear though.