Ramp Test Trouble

Hi everyone,

I was looking for some answers/help. I am a new biker so I did the Ramp Test to see what my FTP is as I am training for an IRONMAN. I have a wahoo kickr core. It was going great and getting hard and then all of a sudden when it was super hard to turn my gears it got a little easier (see picture in the dip) I think my chain had a lot of resistance and jumped a gear possibly (I heard something). I had erg mode on and it wanted me at 340 W but I was at 196. Thought erg mode kept you at the designated power? Can someone please explain to me what happened/tips? My FTP was 244.