SX50 HS Auto focus disappointing indoor?

Taken with the SX50

Taken with the SX220

Flash used in both.

Just got my SX50 this afternoon, I find the auto focus indoor quite disappointing when you have zoomed around 400mm and +. I have compared it with my Powershot SX220 HS, the latter has a quick and perfect focus indoor. And I have compared both on the same subject indoor, the SX220 gets it quick while the SX50 struggles and at times can't get the focus right. Is that normal? Autofocus in on "flexi zone".