Strange soloing

Hi, I’m sure this is easily fixable, but I can’t figure it out. I’m recording simple midi on just a couple tracks and when I record something new, I can only hear the new midi data and everything else gets muted. Lane solo isn’t enabled. The workaround I’ve found is to glue the data together and then I can hear everything. This didn’t start happening until a couple days ago and it’s really frustrating. Any help is GREATLY appreciated!
Daniel