What's your question? Ask

This will be a plant that much prefers shade. here is an article that will help:

https://www.gardeningknowhow.com/ornamental/flowers/clivia/clivia-plant.htm

These beautiful plants prefer a coarse, well-drained soil or even a soil-less mix. Here's an article about caring for a clivia, as well as one about how to create a soil-less potting mix.

https://www.gardeningknowhow.com/ornamental/flowers/clivia/clivia-plant.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/soilless-growing-mediums.htm

We suggest that you check on all your growing conditions - is your soil well-draining, have you given it a rest period? Please read this article on how to care for your plant: https://www.gardeningknowhow.com/ornamental/flowers/clivia/clivia-plant.htm. I would check for root rot if the plant has spent time sitting in wet soil.

It sounds like your clivia could use a neem oil treatment or two. Here's an article that will help:
https://www.gardeningknowhow.com/houseplants/hpgen/powdery-mildew-treatment.htm
You can check your plant's growing conditions with the tips in this article: https://www.gardeningknowhow.com/ornamental/flowers/clivia/clivia-plant.htm

Some species do not have elongated stems. This is indicative of a specimen closer to a wild specimen than the modern ones. This could mean that the plant this came from was grown from a cross pollinated seed, or that it is, simply, one of the short-stemmed types.

You can try a few things, though.

After testing your soil for deficiencies, you can add a little potassium and phosphorus to the soil. This can help with stem and bloom formation.

You can try decreasing the amount of light that the plant receives. This can force stem elongation in response to a slight lack of light.

Other than this, you may be stuck with a low flowering type.

Here are some article that will help:

https://www.gardeningknowhow.com/ornamental/flowers/clivia/clivia-plant.htm

https://www.gardeningknowhow.com/ornamental/flowers/clivia/getting-clivias-to-rebloom.htm

https://www.gardeningknowhow.com/ornamental/flowers/clivia/problems-with-clivia-plants.htm

Here's some info that may help:
https://www.gardeningknowhow.com/plant-problems/disease/plant-leaf-spots.htm

Also, a red flag went up when you said it was planted in a large pot. When repotting plants, they should only go up one or two sizes. If the container is too large, it causes too much moisture to be retained in the soil, essentially overwatering the plant. That could be what is going on here.