19 month old bedtime problems

Jo
My 19 month old has always had a 8 o'clock bed time (9 now that we are in daylight saving time). She's always been really good at going to bed, even after transition to toddler bed a few months ago. She's also been having really long afternoon naps lately (sometimes 2+ hours). The problem is the last few weeks she refuses to go to bed and keeps getting back up repeatedly for more than an hour. If I shut her door she screams (only ten minutes or so but I feel terrible) then puts herself back to bed and sleeps. Do I keep shutting her in and hope she gets the hang of it again soon (maybe just unsettled by the holidays)? Or should I cut her nap duration during the day? Any advice welcome :)