All LED bulb manufacturers have their own designed electronics. Sometimes even between bulb models.
So they may not work with a particular design of any dimmer. X10, Insteon, UPB, Z-Wave or manual knobs.
The difference in the design of your old module and the new module. May cause completely different results.
That does not mean the new module is worse than the older one. Just it does not like your LED bulbs electronics, that the older model was OK with. Another brand LED maybe 100% fine with the newer module.
Also you can not compare an Insteon 2456D {old or newer hardware} with an X10 LM465 {before or after Soft Start} as they are completely different designs. Acting differently with an LED bulb.
Many here, have had to try different LED bulbs to find a good combination.
Insteon users have also had to pick compatible LED bulbs for their setups. So this is not an x10 only issue. More like an automation wide issue.