Thanks to @NomadTech we now know that most likely, Luminus has changed something in their dimmable bulbs since we received a couple of reports from user who recently tried to have Zooz dimmers control Luminus bulbs and experienced flickering. @NomadTech mentioned his GE dimmers work well with Luminus bulbs he bought a while back so we sent him a Zooz dimmer to see if it would work well with them as well and sure enough, they do, no flickering as with the newer Luminus bulbs.
This is just to give everyone a heads up that Luminus must have updated their product, possibly changing the driver which results in incompatibility with the Zooz dimmer (and possibly also the GE dimmer).