When we lived in Connecticut, I had a Clivia that bloomed regularly in the spring. The secret was that from late fall to midwinter, it was kept cool and dry. It only got enough water to keep it from shriveling up. After, February, I started watering and fertilizing again. I am growing one in the ground now, and it finally bloomed after 10 years!
The Florida winters are not cool enough.
Your method was a little drastic because the plant does not need complete darkness, just less water and cooler temperatures.Give it a little more light and a drink and see what happens.

Regina

Thank you for your reply. Is the basement (65-ish F.) cool enough?

Msbumble..Remove the bag ASAP...Although Clivias go dormant during winter, they still need light..

I believe you got confused when you heard they need to rest/dormancy with other plants like Poinsettias, Amaryllis and Kalanchoes.

Clivias are in the Amaryllis family, but unlike Amaryllis, (that requires 6-8 weeks of total darkness to flower,) Clivias need some light.

First, how old is your Clivia? They start blooming approximately 7-yrs-old.
Roots need to fill the pot, (rootbound,) before they flower. I notice, when I repot my Clivia, the following year they either bloom very little or don't bloom, period.
They need a balanced fertilizer during growing period. 'I stop feeding my Clives in Aug/early Sept.'
They do fine in an east window..Cool temps. 65F is perfect. Soil should dry thoroughly..If you have any doubt, insert a finger deep in the soil..if it comes out moist, refrain from water..On the other hand if soil is bone dry/cracked, give a drink in the morning. A sunny day is best. Do not fertilizer..
Clivias start blooming anytime between late Feb until July. Once buds form, place in brighter light, and water more, but never let soil stay continuouslyy wet.

They enjoy summer outdoors in a shady area. As Clivia matures, you'll see more flowers. Good luck, Toni

Mine bloomed every year. I placed it at the bottom of my plastic make-shift green house. It was cool and drafty in winter (not below 34*). I watered it sometimes and every feb it began to bloom and what a nice show. Yellow is the rare color.