Do you have a picture you could share?

Maybe it is from the wood drying out? This video might help, although it is about splitting wood in furniture

https://www.youtube.com/watch?v=NAWz4wd9LXg

The wood has probably gotten dried out. At this point you could use wood filler in the cracks, but then you'd need to paint over it with the same colors. Maybe embrace the cracks? More rustic looking!

Try filling the splits with wood glue. Use toothpicks and Qtips to force the glue in. Gently wrap rubber bands to see if the splits close. Even if they splits don't close the glue will prevent any further splits

I agree, you can fill it or leave it as is.

Maybe this will have some useful info it you can use.

https://www.hometalk.com/20747341/q-i-need-to-repaint-my-nutcracker

here is more info for you https://www.google.com/search?rlz=1C1CHBH_enUS787US787&q=how+to+stop+a+crack+in+wood+from+spreading&sa=X&ved=2ahUKEwjg-cShqKbtAhUXa80KHRHwCc4Q1QIoAnoECAcQAw

Hello A photograph might show your problem best to get best reply to correct your situation.

I would suggest using Elmer’s wood putty to fill defects and acrylic craft paints to touch up repaired areas. Smooth filled area with moist finger to get smooth repair and not need sanding. Hope this helps.

Hi Cin: Sounds like the wood is getting dry. Sometimes the wood will crack because of fluctuations in humidity and then dryness, like by a window and then the AC or heat comes on. Sometimes it comes from washing the article with water. You can fill in the cracks with wood putty, and when it dries, you can wax over it or paint it to keep it from cracking further.

Hi! I agree with repairing the cracks. Use paintable wood repair materials. Good luck! Stay safe!