Replying to K2/Full tilt boots causing serious foot pain

So I used to ride the full tilt konflicts, which were discontinued after 2014. They had an 8 flex tongue on a 1-10 scale. These boots had seen their days and I had to get new ones. I bought the k2 revolver boots with the 90 flex tongue (quite a bit softer) and the traditional liner as opposed to the intuition (konflicts had intuition.) However since then, I have noticed that I have almost too much movement in these boots where my feet have to compensate to keep my balance, as opposed to the boot keeping me more locked in, which I think is mainly due to the softer flex tongue but I am not positive. As a result, I more often than not get a sharp aching pain in the arches of my feet, similar to using a new pair of ice skates for the first time or something, hoping someone knows what I am talking about. But it makes skiing pretty miserable when it happens.

I just can't figure out if it's due to the flex of the tongue, the liner, or the boots just not being as broken in, maybe all of the above? The konflicts I got back in 2014 were heat molded to my feet which may have something to do with the noticeable difference.

I guess my question is, should I try getting a stiffer tongue and potentially get the boots fitted or do you think it's just not the right boot for me? (which I can't imagine considering the boots are basically identical.) Also, if it is the tongue flex, does anyone know what a full tilt 8 flex would translate to with the k2 scale? I know the old drop kicks were a 6 flex, so I am thinking maybe 100 or even 110 flex on the k2s would be equivalent but am not entirely sure.

Any input would be greatly appreciated.