Do you need a screwdriver to dim the older one and a knob on newer?
The current version of these grow lights come with a dimmer knob and daisy chain capability. The first generation did not feature daisy chain, and the dimmer needed to be adjusted from underneath the driver.
If that's you then probably not, if both are knob type ie daisy chain and your problem exists then it is possible you have a problem.
This is common with lights that use drivers/dimmers mounted direct to light in tent conditions from heat/moisture during use.