Just an FYI,
LIFX did some cloud work and right after that, I noticed my link to ST was no longer there. I also lost control of all LIFX lights via ST, but not Alexa. Based on that, I took a look at the link within ST and noticed it wasn’t logged in any more. If you are having issues, you might need to log back into LIFX via the ST app to re-link them. It looks like the cloud-to-cloud link dropped during their maintenance.