Bulb shows as offline, but I can change its color and brightness, but I cannot turn it off.
What have you tried to correct it?
I would unscrew the bulb, leave it sitting out for about 2 minutes and then screw it back in and see if it connects for you.
After having white bulbs for several years, with one in my bedroom to turn on and off by rules, I had the opposite of your issue. The bedroom bulb did not turn on by rule and although I could turn it on and off according to the app, it did not light up. The app did not indicate any connectivity issue, the bulb just wouldn’t respond.
I manually turned the light socket off and back on, and the bulb reset and worked again as expected.
Customer Service Rep: “Have you tried unplugging and plugging it back in?”
I have had this experience too the last couple of weeks! And it’s always random bulbs. I just turn them off physically and back on and they’re good again until they decide to not respond.