23 Prime not entering EV mode after pushing EV button

Long time reader, first post. I went from a 2014 Prius to a 2023 Prius Prime in August and everything was working great for the first few months. Recently, when I press the EV button the car does not enter the EV mode and can take anywhere from 1-5 minutes to engage the EV mode and begin showing kwh information. While waiting for EV to engage the usage mpg/kwh indicator stays at zero and shows no information regarding kwh or mpg; everything is at zero during that time. When I look at the energy use indicators (dash and media) it shows that the vehicle is using the ice engine. The EV mode button is indicated on the screen, but the second EV mode is not showing up. This has been happening for about 2 months in weather ranging from 20-80 degrees. The guy @ the dealership was of no help as he just said that the car (Prius Prime) will only engage the EV battery doing 25-30 when I asked him about it not engaging on the highway. Has anybody seen this or have any tips or suggestions? Cheers