Teething Problems/Troubles:

If someone or something is having teething problems, or teething troubles, they're having problems during the early stages of something.

The government had a few teething problems early in its term, but most people think they did a good job overall.

We're still having a few teething troubles, but when everyone adjusts to their roles, everything should be fine.

Origin: Related to the fact that babies go through a painful stage early in life called "teething", during which their first teeth are growing.