If the 73743 Is the “paramedic light switch” mentioned in your first post, then it’s simple.
That device, like the Hue dimmer switch, Is capable of joining with its lights even when no hub is present.
When the power went out, the hub went off-line. The lightbulbs started to panic trying to find the hub. The dimmer switch, as a battery operated device, continue to operate, and the bulbs grabbed onto it. So now they are paying attention to it and probably not paying attention to the hub. In any case, that switch can operate them without any automations at all, which is likely what you are seeing.
The fix is easy if tedious. You have to remove all of the affected devices, the lights and the switch. Reset them, and add them back The same way you did originally . Then everything should be fine for now.
But to avoid this problem recurring with another power outage, you should use a different device for your paramedic switch.
What DTH are you using for the Sylvania switch?