Flightradar24 shows the aircraft type as “32Q,” which is the NEO, for EI 156 on October 1st and 3rd, and the NEO being used for EI154 on October 2nd.
The EI webpage shows the same thing, the NEO being used for the two different flight numbers starting October 1st:
EI 154: Monday, Wednesday, Friday
EI 156: Tuesday, Thursday, Saturday, Sunday