Recalls can be for things as minor as mis-labeling. Or as serious as a seat that will not function properly at all in a crash. Nearly every brand has had at least one call at one time or another.
They aren’t indicative of an unsafe seat. Recalls mean the company is listening to consumers, constantly testing their seats and making sure to issue recalls if they find any issues.
Mandatory recalls are the other type of recall– these types are rare since the manufacturer usually issues their own recall before being forced to do this.