Might be too much sun all of a sudden! The leaves turning pale is a giveaway! I think you should slowly acclimatize newly purchased plants to full sun. Even though Greenhouses seem sunny and bright, there IS plastic covering them. I think, outdoors, they prefer morning sun or filtered sun. The chewing is probably slugs. BIG ones...(you DO live in Texas!):-)

Also, don't be surprised that your Polka Dots eventually grow to about 10-12" tall. They also send up a spike at the end of summer with itty-bitty blooms on it. PD plants are sprayed with a growth retardant so they look cute and compact when sold. That spray does not last forever!