Fwiw the TP link bulbs usually have a local API that Home Assistant has an integration for. You can use that and block their internet access - unless they've removed that feature. I only used one of these briefly because someone gave it to me. Usually just use cheap ZigBee bulbs. I would throw that one out though as someone else said it's likely been compromised already...
The zigbee bulbs I've had the best luck with are Innr, although they are kind of pricy. Ikea bulbs are good for the price, but every one I have, has very loud coil whine when off. I had some on bedside stands and had to move them to other rooms. Sengled are nice when they work, I've had issues with them dropping off my network.
Both Ikea and Innr are also repeaters, Sengled does not do repeaters in their bulbs. Neither Ikea or Innr are exactly cheap, but they've been the most solid for me.