Brown edges sound like a water issue to me and definitely NOT like HVX. When the temperatures rise there will be greater need for water supplementation simply because it evaporates faster. A recent Hosta transplant needs to be watered in well regardless and with the whacky weather it spells trouble for new transplants. Water it, regularly, and I rather suspect you will see newer growth developing in about 3-4 weeks that will not show the brown edges.

Take a look at the link below to see what HVX looks like.

Here is a link that might be useful: HVX info

Definitely water issues...I completely agree. Those large leaves lend to accelerated transpiration. Water deeply two times a week!