Kwikset deadbolt rust prevention
Had similar issues at my sister's Florida condo. Had to replace a ton of hardware due to corrosion. All hardware (exterior and interior) rusts or degrades there due to marine environs. I would contact Kwikset and request replacement trim rings or whatever has gone bad. Do NOT spray anything into/onto lockset. You'll just have a worse situation. No oils or corrosion sprays. Or replace the whole lockset. Stainless steel would be very expensive. Keikset would not be my first choice.... Bargain Schlage as sold in the stores didn't survive this moisture onslaught either.