Our HC had the same problem though not quite as bad. I 'temporarily' fixed it with Eternabond tape - then forgot about it until this thread. Oh well, spring is just around the corner
Oh and that gap, it's nice open doorway to critters and most likely whay we had mice this spring since the extension cord I use to keep the battery charged, hooked the corner, probably when I used the snow blower and moved the cord. Made for a nice walkway.