How do I know when it’s time to move on?

I've been trying to become more attuned to when I'm becoming unhappy rather than reacting to it once I'm already there. So starting to try and pick up on signs: am I feeling disengaged or disenchanted with what I'm doing? That obviously means that something needs to change and trying to figure out, is there something that I have loved doing recently? And do I need to do more of that, and to incorporate it more into my work.