Replaced bridge with pro - one set of lights now flashing when using alexa to turn on

Dunno if anybody has encountered this before but today I swapped out a Lutron Caseta bridge for the Pro so I could integrate with Hubitat.After I finished adding all Caseta switches to the bridge pro, I have one set of lights that when turned on and off with Alexa, about 75% of the time the lights flash on and off every second or so. They work fine when turned on with the physical switch. I had zero issues with the lights which have been on the old bridge for 9 months and the bulbs are Caseta compatible. I googled a ton and people kept saying to replace bulbs with compatible bulbs. Not the issue here so I haven't found any useful info. Any suggestions appreciated. Thanks!

update, i used alexa to reduce brightness 10% at a time. when i got to 10% the lights stopped blinking. i then told alexa to increase to max and no issues. so i've found if lights are off, and i turn on to 10% (via alexa), then increase to max (via alexa), there is no blinking.perhaps it's working with the switch because it gradually fades up the brightness vs alexa which jumps straight to the max state?? i'm not sure what to do with this info though to solve the problem

I have the exact same issue, I’ve tried it with Alexa and Siri and both cause the flashing issue when turning the lights on. Don’t have a Google device but I’m sure it would cause the flashing as well. The only way to get them to stop the flashing when turned on is to set them to 10% as mentioned and then ramp up to 100%. I’m using the non-neutral PD-6WCL and have contemplated replacing it with the ELV model which does use the neutral, but at double the price of the PD-6WCL and no way of knowing that it will fix the problem I’ve been reluctant to do it.

Same issue. A few weird variations. Two PD-5's were working fine until installing the last dimmer in system, a PD-10 (without neutral) Noticed a slight occasional pulsing in PD-10. Then noticed the PD-5's were flashing. Three lights in various locations in the same scene together. Same issue whether through Siri or Dimmer control. Deleted the scene they were in together and rebuilt as I had added later the PD-10 and though, why not try. That seemed to take care of the problem, for about a half an hour. Deleted the scene again. No joy. Reset to factory program. That seems to have worked for now. Some weird but inconsistent things. When one PD-5 was flashing, if I hit full up on the dimmer, it would stop. Sometimes. After Resetting and turning on for the first time, they flashed once and then have been stable.Things I will be checking tomorrow;Which phases are they on.If I take out the PD-10 will the PD-5's operate properly in a scene.If not, will swapping to known working PD-5's resolve the issues.Check polarity just for fun.Grounds are good.The lights the PD-10 is controlling are the only direct dim LED's in the system. All others have 120V powered drivers.Will let you know how it goes.

Sorry, PD-6's not PD-5's. Also, forget the theory of poor communication from the Dimmer to the bridge. After an hour, I turned off the factory reset PD-6 and then back on and no amount of fooling around would stop the on/off oscillation.

Yay, used the dumb setting and finally uploaded images.

Looking at the misbehaving dimmer on a scope, it keeps trying to fire as if there is not enough current to make the thyristor latch. The led indicator on the dimmer itself indicates full operation. When the unit finally does fire, it is a rather malformed sine wave flattened sharply at the top with a last second spike to the peak giving an RMS voltage of only about 86 - 90 volts. Peak to Peak seems about on par for the dimmer.

If this was a generator, I would say there was something feeding back to the exciter coil causing the issue.

Checking a properly operating unit, I am surprised how much voltage it eats. All semiconductors lose a bit of voltage owing to voltage / current (depending) needed to start operation. But these things eat up nearly 10 volts instead of 2- 4 volts. Have to say I'm SLIGHTLY disappointed. I guess they are playing it safe with headroom on the capacities of the components. They also have a fairly large breakover voltage. (enough current present to begin operation). Almost like they are using diacs or inverted pair scr's set up with resistance triggering. This has no ill effect on operation, it just makes me want to open one up and see what's going on. I think I need to order one more PD-6, perhaps buying one extra to sacrifice is in order.

Having said that, they do operate very smoothly with very minimal ringing.

One PD-10 and PD-6 are on the same breaker, the other PD-6 is in a sub panel and will check phase today.
I will look for feedback, possibly from the PD-10 as the blue wire used for triggering seems to have a substantial voltage present, but have yet to put the scope on it.
Oh, yeah, so the PD-10 is operating with a mechanical 3-way and one pico.

Unfortunately, this is the last thing on my plate and I am getting to this only at the end of the day.
Will stop back with more results later or tomorrow.

The 3 images being, my mains voltage, the misbehaving dimmer with an operating load (not flashing), and a properly operating PD-6 full up.

So, it was a feedback issue. From the LED driver itself. I didn't have the time or patience to delve further. With new LED driver the dimmer looks fine on the scope.

So, unfortunately the only thing I have to offer the other folks dealing with this that don't happen to have a scope meter in their pocket is to get a good Volt/ohm meter that reads True RMS. (I've used many and General makes a great one for cheap with better basic accuracy than some of the big names.)

If you find the reading on load side more than 10 volts below your mains (a lot more), consider something might be feeding back to the dimmer and go from there.