I highly suggest making differences between solo and grouping in Cogah mode.
We all want to get the most out of Cogah mode for the better rewards, but right now you are kind of "forced" into group play if you want the most rewards, as its way easier to stay in Cogah for a "long" time compared to when you do it solo.
I think there should be some +/- scaling to enemy difficulty¨(In Cogah) so that the large amount of solo players arent playing at a disadvantage or feel pressured into playing with randoms.