My guess is that it’s likely just characteristics of your bulbs. The dimmers are probably a bit different technology-wise and may cause different bulbs to respond differently. Some tested bulbs that work (and don’t) are in this thread: Compatible Bulbs for Dimmer Switch (Gen 2). You could consider adding your experience there, too.
One suggestion: could it just be that the bulbs don’t like super-low (or high) levels from the dimmer? You can experiment by using ST to dim them to various levels, and set the “minimum dimmer level” and “maximum dimmer level” preferences to what you find works best, if that happens to help with your problem. I only have one of these dimmers controlling actual bulbs (the rest are on smart bulbs with no direct local load control), but I did have to up my “minimum level” a bit to prevent the bulbs from just turning off. This isn’t exactly your problem, but maybe you can figure something out if you play around with these and other settings.