It looks a lot like sunburn that is starting to heal to me. Is this a newly rooted cutting?

It would appear to me to be sunburn related as well.

It’s been a while but the cracks seem to be getting worse. Not sure if it will eventually go away or if there is something I can do to fix/cure the issue?

Time is about the only thing you can give it as far as repairing the damage. I would consider raising the plant up in the container and giving it more room for roots and growth to make it as healthy as it can be. Also assuming it will be protected in these areas to prevent additional damage and giving it a chance to heal.