What in the bazingazoinga could be happening with my string of pearls?

Was watering my funny little plants when I saw these strange little wrinkles on some of the leaves.

The pearls are housed in a gritty high drainage soil and I take multiple safety measures against pests so I'm pretty sure it's not a mold or pest problem.

Could this be a fungus? Can it spread to other plants? Should I remove the affected pearls? Please help I am worried for my little guy