As a big fan of switch hitting striking (having been trained that way as a kid)
You gotta be all or nothing with it.
Either you are:
punching thru a shifting combo in which case your offense is your defense because you are utilizing pressure to force your opponent to defend
Or you have to be OUT OF RANGE when you switch
There is a little more to it when you talk about suff like the "Pep step" aka the V step which is going to switch stances and flank your opponent on the break (great move, Usyk, Lomachenko and Mike Tyson all used well and old timer Willie Pep...)
Both izzy and Leon got caught in no man's land.
A tactical mistake and props to their opponents and presumably their teams for catching that and taking advantage