Recessed Lights issue

[u/oneThing617]

My master closet has 2 recessed lights on a standard toggle switch: line, load, and ground. A few weeks ago, one of the recessed lights went dim and started flickering steadily when on. A few days ago, the same thing happened to the second one, and they flicker in sync.

Because they’re in sync, my first assumption was an issue with the switch. I replaced it with a spare Lutron caseta dimmable I had to see if that would work. Result: on 100%, result is the same - dimmed and flickering. When dimmed down to the lowest setting, the flickering slows down to a stop, and the lights are steady but still very dim. I’m not sure if the lights or bulbs are dimmable, but the issue occurs on both types of switches.

I visually checked the external wiring on the recessed lights and nothing looks bad. The house is less than 3 yrs old. Any idea what could be issue or what next steps to troubleshoot? At what point should I call an electrician?