Q.Kangaroo paw plant
Kangaroo paw was doing great but was too big for the pot so divided into two pots four weeks ago. Plants look like they are dying now. What’s wrong?

Kangaroo paws prefer slightly acidic soil, so you'll want to ensure that not only was the original soil divided evenly between the two plants but that any new mix matches the the composition of what the plant originally thrived in (in other words, make sure the new soil is as close to the original soil makeup as possible). If you relocated the two plants to a different location with different sunlight situations, that could be stressing it out as well. If you have a drought-tolerant variety and you gave it a healthy drink of water after you split it (when it's not used to that much water), it may have thrown it into a bit of shock. If that's the case, let it dry out just a bit (and make sure it's not getting sunburnt) and wait. It should recover, even if very slowly. Make sure the soil, sun and water situations aren't too drastically different from what they were before you split the plant and check it for pests such as spider mites. Here are some articles that may help you:
https://www.gardeningknowhow.com/houseplants/kangaroo-paws/kangaroo-paws-houseplant.htm
and
https://www.gardeningknowhow.com/plant-problems/pests/insects/spider-mite-treatment.htm