That's sounds like a wiring issue. I've had Baja Designs on my truck since 2017 with hundreds of hours of use with not a single issue. If they are flickering, you could have an issue either with your wiring or wiring in the harness. I'd be really surprised if something that new had an issue with the diode. I'm sure it's possible.
Anything is possible, but I’m going to say that a wiring issue is unlikely. I pay a great deal of attention to my wiring jobs (each crimp) and based on the fact that one light flickered and the other did not (wired to a Y-harness I built), there is only one connection point that could have failed to cause that. The lights have seen no moisture, rain, etc, and they didn’t flicker when they were installed in 2021 or whenever it was (around then). The connections looked good upon removal.
But these are some of the best in the industry, and Rigid isn't even in the same class.
Not really sure what this means but I’ve owned possibly 20 different rigid products and not a single one has exhibited any failure, moisture, etc. The Rigid fog lights on my truck have been on with the headlights since install 3 years ago, and so they also have tons of hours on them. Not to be derogatory, but usually comments like that are fanboy, opinion based statements and are not based on comparing actual light output, pattern, color, or longevity.
It doesn’t help my bias for Rigid that Baja Designs doesn’t understand what the color amber is, nor do they understand what an SAE fog pattern is. Yellow with a green tint is not amber. Lights that blind people or are hard to look at are not fogs. I can’t take anything I’ve seen from Baja compared against a Rigid and say I think anything they make is truly better.
The two potential Rigid downsides I can think of are cost, and the fact that you can’t change the lens. On cost, I get considerable discounts from someone on another forum, and for the lens stuff, I find I haven’t gotten the desired result wrong yet. Whereas following Baja’s advice for backup lights, I got the wrong lens for my use. So as long as I can avoid that, I’m ok without being able to change a lens. It is a nice feature though if needed or if plans for a light change and you move it to a different spot.
That said, just for curiosity, I’ll hook that light I claim is faulty up directly to a battery and see if it flickers. If it doesn’t, I’ll rightfully admit as such. It didn’t flicker all the time so I may have to wait a bit to get it to act up.